Topsy’s co-founder and now former CEO, Vipul Ved Prakash, will remain the company’s main technical guru while he becomes CTO, and will run platform and product engineering.

Greatwood’s job will be to scale the company up, which sounds like it will be interesting. I talked with Greatwood and Prakash yesterday, which was Greatwood’s first day on the job.

With so much social data being created on Facebook and Twitter and so many other places, Topsy was built to index it all and make it searchable, and analyze it. “There’s a lot of exhaust that’s being created around analyzing social data that applies to so many businesses, from finance to publishing,” Prakash told me.

Greatwood said that what attracted him to Topsy was the fact that it’s a lot more than a search or analytics engine. “It really lets you extract some deep analytics information from a broad array of data sources,” he said. Think about all the time and effort a company devotes to analyzing who and how many people visit its Web site using products like Google Analytics or Adobe’s Omniture. “At the same time there are probably lots of conversations taking place about that company or just conversations that company would be interested in,” Greatwood says.

Sales are starting to take off, Greatwood says, and though the customer base is small right now, there’s a great deal of interest from the marketplace. “We have a small number of customers, but within that group there’s some very big customers, and they’re driving an acceleration of sales over the past few months.” He wouldn’t divulge many customer names, but one that’s already been disclosed is AOL’s Huffington Post. The plan is to take Topsy’s products to a broader market during the year.

Topsy raised $15 million in a Series C round led by BlueRun Ventures in March with prior investors Western Technology Investments, Ignition Partners, Founders Fund and Scott Banister, the founder of Ironport, participating. Its total capital raised so far is about $30 million.

The funding is particularly notable because Topsy is part of the much-maligned Twitter ecosystem. The San Francisco-based company’s search index consists of more than eight billion tweets.

Perhaps the only other Twitter ecosystem start-up of Topsy’s magnitude is UberMedia, which has raised some $21 million in VC funding and gobbled up various Twitter clients. Twitter blocked some of the company’s apps for three days last month, saying they violated multiple
policies.

Twitter competes with both start-ups, offering its own search site and software clients for various platforms.

Besides running its search site, Topsy also provides analytics tools for marketers and widgets for publishers including IDG Media, The Huffington Post and Discovery Communications. The company brags that its search is super speedy (capable of processing over 1 million documents per second) and smart (ranking results based on social graph analysis, which Google and Bing are only starting to do).

While BoomTown does not usually do funding announcements, the $7 million that the adults-only social network Zivity will be announcing today is interesting for one reason.

No, not the fact that it builds its business model on the back–well, back ends, to be more precise–of photos of women in various stages of undress.

Get your minds out of the the gutter!

It’s because it is one of the few Web 2.0 companies that is trying out a subscription business model, as opposed to every other online company these days, all of which are chasing ad-supported nirvana.

Today, the San Francisco-based Zivity is nabbing that $7 million from BlueRun Ventures and Founders Fund, both of which have backed social-networking widget phenoms like Slide.

In fact, Zivity co-founder Scott Banister is on the board of Slide and was one of its earliest investors. (Banister, whose wife, Cyan, is also a founder and model on the site, has also been involved with a wide range of start-ups, from Overture to PayPal to IronPort.)

So instead of, say, Viagra banner ads, Zivity users pay $10 a month to look at the “tasteful” naked ladies pictures uploaded by users. The company must approve of the professional-quality photos, using a series of guidelines (no sex acts or close-ups, for example).

“Look, Lindsay Lohan just did a whole photo session similar to what we have on our site, so what’s wrong with 3 million other women wanting to do it,” joked Banister in an interview last night, referring to the recent series of pictures the troubled actress did a la Marilyn Monroe for New York magazine. “We are creating a place where the more controversial material can be published online without worrying whether advertisers are willing to underwrite it.”

Well, we will not get into a debate as to why we probably should not be playing copycat with the train wreck that is Lohan. But Banister does have a point about the need for different kinds of business models that don’t rely on advertising.

In fact, Zivity–which was seeded in 2007 with $1 million in funding–pays contributors who are more popular in a revenue-sharing plan via voting. Right now, for example, the most popular “photo sets” includes images of Cupcakes, Pearl and Damanda (pictured here).

There is also an increasing element of social networking, among the models, photographers and others, which does mimic more straight-laced sites.

In the press release for the funding, Banister compares Zivity to the popular cable channel HBO. “We think of Zivity as the HBO of the Internet,” he said. “Unlike free social networks and other user-generated content platforms underwritten by advertisers, our subscription-based business model offers us real freedom–to publish uncensored content and to pay our content producers generously.”

While the site is only comparable to HBO if it ran only “Taxicab Confessions” and “Real Sex” in an endless loop and you had never heard of “The Sopranos” and “Entourage,” its sure-fire subscription base might allow Zivity to be one of the few Web 2.0 companies that survives the coming washout.

But before you fire up that browser, the site has only 10,000 beta users now, with another 30,000 on its wait list. While you can sign up to get an invite or be invited, the open public launch is not until 2009.