In fact, co-founder Ivan Kirigin’s first day at Facebook was last Monday–four days before he and his wife, Abby, announced that they are shuttering their start-up.

Confused? You should be: This is one of the odder M&A stories I’ve seen in a while. Not surprisingly, the tale differs depending on who’s telling it.

Some basic, undisputed facts: Sometime this spring, TipJoy, a year old start-up that lets Web surfers “tip” bloggers and publishers, shopped the service to multiple parties, including Twitter and Facebook. By July, Facebook had offered, via a term sheet, to buy the company. Facebook then pulled its offer, and shortly after, offered Ivan a job. Now he and his wife are shutting TipJoy down and returning what’s left of the $1 million they had raised to their investors.

Also undisputed: No one has accused anyone of violating any laws, or contracts. Facebook’s offer was nonbinding and nonexclusive. And it’s not unheard of for companies to walk away from an M&A deal late in the process. That’s what happened, for instance, when Google (GOOG) bailed out after deep talks with Digg a year ago.

You could see why some of TipJoy’s backers, which include BetaWorks, the Accelerator Group, ex-Googler Chris Sacca and the Y Combinator start-up factory, might cry  foul. The argument would be that Facebook’s actions effectively prevented the company from finding another buyer. But even if that was true, it doesn’t mean that Ivan Kirigin had to accept Facebook’s job offer and/or shutter his company.

Facebook spokesman Larry Yu declined to discuss the negotiations in detail, but offered this statement via email: “We take pride in operating in a transparent and ethical manner. We can’t offer any specifics here, but to suggest anything untoward occurred on our part simply ignores the facts.”

I’ve sent the Kirigins repeated requests for comment but haven’t heard back. Their statement announcing the decision to close their company doesn’t mention Ivan’s new job. But it does hint, obliquely, at their future plans:

When we evaluate why there’s been so much hype about payments on Twitter, and yet so little traction for us (and even far less for our competitors) it is clear to us that the reason is that a 3rd party payment service doesn’t add enough value. We strongly believe that social payments will work on a social network, provided that they’re done within the platform and not as a 3rd party….the only way to get around this is for the platforms themselves to control payments–then all people wanting to operate on that platform would have to play along. We believe that a payments system directly and officially integrated into social networks such as Twitter and Facebook will be a huge success.

UPDATE: Y Combinator founder Paul Graham, commenting on this story on his Hacker News site, says Facebook hired Ivan at his urging:

Facebook didn’t do anything wrong. Tipjoy was out of money. They’d been talking to several potential acquirers, including Facebook, but those deals all fell through. So the Tipjoys were going to have to get jobs somewhere. Since they were worried about money and Ivan admired the hackers at Facebook, I asked FB if they’d offer him a job, and they did.

It doesn’t portend anything for the future of startups, as this story seems to imply. If your startup tanks, you have to get a job somewhere, and lots of hackers get jobs at Facebook. There are several other YC alumni working there.

Ivan Kirigin also weighs in within the same comments section, and says that my report “completely doesn’t tell the whole story.” Ivan, I’m all ears, so either drop me a line or leave a comment below.

Note: I’m assuming that the commenters identifying themselves as Paul Graham and Ivan Kirigin in the comments section are indeed Paul Graham and Ivan Kirigin. But I’ve sent emails to both men so I can verify that. Update: That is indeed Paul Graham.

The big picture: Even though Facebook’s official valuation has slid from $15 billion–November 2007, when Microsoft (MSFT) invested–to $10 billion, Zuckerberg is OK with that, arguing that 1) that deal was done at the peak of the market and 2) the pact was never really a financial deal, but a way for Microsoft to partner up with Facebook–and, though he didn’t say it, to box out Google (GOOG). That sounds pretty reasonable.

Zuckerberg’s main talking points were that his company didn’t need the money, but it sure was nice to have, both to fund growth and make any M&A easier to pull off. And when it came to his new partners, he argued that DST’s existing portfolio, which includes several other social networks, would provide models/examples for his company as it continued to expand outside the U.S.

Earlier:

Facebook and its newest investors Digital Sky Technologies, are holding a teleconference to discuss the $200 million at 10 billion valuation deal the two parties just announced. I’ll be covering the call live.

Call starting “momentarily.”

On the call: Facebook Mark Zuckerberg, DST CEO Yuri Milner. Also, via phone (from D7!): Facebook COO Sheryl Sandberg and DST’s Alexander Tamas.

Zuckerberg reading statement that more or less tracks press release: “Advertising product” improving, “our business is doing really well” and we’re on track to create a “nice” business, and that’s why investors want in. DST approached us, has interesting profile and experience and insight into social networks. “We found their thinking and their leadership to be really impressive.”

Money provides “cash buffer” to support our continued growth, also possible other moves. No specific plans to talk about “but nice to have flexibility.”

Milner: “I realize not all the participants on the call are familiar with us.” Goes over DST portfolio. “We have now started to actively expand abroad.” We’re a holding company, have raised and invested more than $1 billion since 2005. Rattling off portfolio companies now.

Q&A:

What does this mean for possible IPO? Zuckerberg: “Our approach to financing has really been that we want to take money and work with partners”…”for a lot of start-ups, you get the feeling that the IPO is really the end goal…that’s not the case for us…we’re not rushing toward it…that’s really all I have to say about that today.”

What’s valuation for common stock? Zuckerberg: No comment. “There are different transactions that we’ve structured differently…we hope that there will be different things in the future…probably sometime in the next few months.”

What does this say about Microsoft’s $15 billion valuation? Zuckerberg: We did that deal at the peak of the market. That was part of a broader relationship. That investment was just one piece of it. This is also a relationship that we’re forming with DST…we hope we will work with other things over time.

“We feel really good about the progress we made…we feel this is  a good and fair valuation for us.” The Microsoft deal was at peak of market and was a strategic deal. “The world was in a pretty different place at that time.”

The international audience is 70 percent of our users. How do you monetize that? Zuckerberg: I have a few things to say, but want Yuri to talk, too. Milner: We have invested in five social networks in Europe. They have been able to monetize better than Facebook because they’re further along the curve than Facebook, which is a global company. But we think that Facebook will improve. Money will come from micropayments and advertising.

Zuckerberg: We can do advertising and have been experimenting with payments. Social networks in DST’s portfolio all monetize in different ways. Each is doing well, with a different model. We’re still growing. Online and direct advertising are growing the quickest, but over time, we expect to be able to build out a large number of these things.

What is your ad revenue going to be? Zuckerberg: A couple of months ago, we felt that everyone outside the company was underestimating our performance. We’ve been EBITDA-profitable for five straight quarters coming on six. Revenue growth has been 70 percent. Cash-flow positive sometime in 2010. That’s important because it means this investment is pure buffer. I realize those aren’t absolute numbers, but those are the ones we’re talking about.

Will DST be involved in management? Milner: We have our own businesses to run. We’ll keep in touch.

Questions about micropayments. Zuckerberg: We’ve tested a lot of things. It’s not a big part of our business, could be greater one day. They create a lot of value for users, and there are ways to monetize them. I’m looking forward to learning how these models are working.

Please talk about common stock/employee stock purchase plans. Zuckerberg: Going back to first question re. IPO. We want to make sure that we can continually make it so employees can be focused on the long term. We felt that if we let people have a little bit of liquidity, it can take some of the pressure off and let people focus on making company as good as it could be. We started to do this last year and had to hold off. Now we hope to be able to do it again.

Will that be the only way you are allowing employees or ex-employees to sell shares? Zuckerberg: Still talking about.

Is current Facebook ad business to be the main business going forward? Doesn’t mean it will be main business in the long term. You guys know everything that we’re talking about now.

Why aren’t you running big brand ad campaigns? We’re very interested in it. We have a big ad sales team. Building out offices internationally: U.K., France, a few more coming up. We think the best way to serve advertisers is to create ads that people interact with, that are “social and engaging.” I don’t want anyone to think that this isn’t a big part of our business, because it is.

Sandberg: Heavily engaged with brands. Ads specifically designed for Facebook, so they look different and behave differently than other ads on other sites, and that’s a good thing.

Preferred shares–are these are substantially similar to the ones Microsoft bought? Zuckberg: “I’m gonna duck that one.”

Does the company have any debt? Zuckerberg: [pause] There’s been some information that’s been public about debt we have for operating equipment. Beyond that, we do equity deals.

Will you do other investment deals? How many did you look at? Zuckerberg: He doesn’t really answer this question; instead he goes on to praise DST. Milner: We see things that other people don’t see, which is monetization that other social networks have been able to do. So we “kind of feel comfortable with that valuation.”

Is this largest foreign investment in Facebook? Zuckerberg: Um… [pause]. There’s been some public information about other folks we’ve worked with, but I think from reading some of the records you can get the answer to your question.

Other new deals? Zuckerberg: It was really at our option to find someone we were comfortable with. We didn’t feel like we needed to take an investment, and now we feel like we have the buffer we want.

Working on video chat product? More international products? Zuckerberg Yes. There are lots of things like that that we’re working on now. We want the site to be available in every country. We’re not translating the site. Users translate the site themselves. And a lot of the features are universally applicable.

Call finished.

That’s because the site is very expensive to run–YouTube served up 5.5 billion videos to U.S. viewers alone in March–and a very hard sell to advertisers, who are scared off by its more-or-less-anything-goes collection of clips. The site doesn’t even bother to try sell ads on more then a small percentage of its videos.

But the latter part of that equation may be changing, argues Bernstein Research’s Jeffrey Lindsay. He thinks YouTube has the ability to sell ads against nine percent of its inventory. That alone represents progress–last year, that number was around three to four percent.

But Lindsay thinks that Google (GOOG) is getting better at putting more advertiser-friendly stuff up on the site, via projects like the TV and movie hub it rolled out last month.

That site doesn’t have anything like the breadth that Hulu boasts, but it’s a big improvement over what used to be there. Lindsay figures that it will get better and that next year YouTube will be able to sell ads on 15 percent of its inventory. His note:

We also note the large increase in advertising on YouTube, which we estimate currently has approximately 9% ad coverage and which we believe could rise to 15% within the next 12 months as more professionally-produced content and movies are added to the Web property. We understand that Google is currently exploring new payment mechanisms–micro-payments and subscriptions to expand YouTube’s business model. Although YouTube revenues are likely to be small through the end of 2009 (we estimate $123 million), we think the increased ad coverage will place YouTube in a favorable position when CPMs eventually start to recover in 2010 and beyond. Our 2010 forecast for YouTube revenues of $222 million represents 81% growth over 2009.

Then again, YouTube still has a very long way to go. Look at the most popular clips on the site today and you’ll find a whole lot of video from this week’s Barcelona-Chelsea Champions League match, all of which seem to be copyright violations, which makes them toxic to advertisers.

Here are four examples from the same game. Note that all of them seem to have been up on the site for at least a day:

But investors are going to be pleased with the non-GAAP earnings number: $5.16 share, up from $5.10 per share in the previous quarter and way, way above the $4.90 per share consensus. Bottom line: Google (GOOG) has cut back on its expenditures, and that’s boosted profits.

Here’s how: “Operating expenses, other than cost of revenues, were $1.52 billion in the first quarter of 2009, or 28% of revenues, compared to $1.65 billion in the fourth quarter of 2008, or 29% of revenues. The operating expenses in the first quarter of 2009 included $774 million in payroll-related and facilities expenses, compared to $890 million in the fourth quarter of 2008.”

And here’s one way to keep “payroll-related expenses” down: Stop hiring people. “On a worldwide basis, Google employed 20,164 full-time employees as of March 31, 2009, down from 20,222 full-time employees as of December 31, 2008.”

Meanwhile, Google is still moving its sales team around following Tim Armstrong’s departure.

Earnings call starting now. I’ll update as we go.

Google CEO Eric Schmidt: “We’re still basically in uncharted territory… users are still searching, but they’re buying less… advertisers are still spending, but they’re spending less.” That’s all appropriate, he says. Google’s auction model is working. Ad dollars are still moving from offline to online.

Apologies: I now have three Google stories breaking simultaneously, and I’m going to have to duck in and out of the live call.

Sorry for the gap. Here’s Schmidt talking about getting long-form content on YouTube: Initial focus will be on advertising, but will add in micropayments and other schemes down the line. Will be announcing additional things in that area “literally very very soon.”

Schmidt asked about Twitter: “It proves that innovation is alive and well in Silicon Valley… it is an incredibly useful thing. The question here is how would you make some money on that… and the logical conclusion would be advertising, and we’d happy to work on that with them.”