Steele is a longtime marketing exec with previous stints at the video ad start-up Tremor Media and Coca-Cola. She comes to Twitter at a time when the company is finally focusing on turning its service into a business. Twitter is expected to have about $100 million in revenue in 2011. It was valued at $3.7 billion in its most recent funding round, and well above that in off-and-on acquisition talks with Facebook and Google.

Steele’s Twitter account is here. Appropriately, we first learned of the news on Twitter, from Advertising Age editor Michael Learmonth. A spokesperson for Twitter confirmed the hire this afternoon.

So here’s a new one: Same cool stunts (to my eyes, at least). More exotic locations. And it looks like it will be a hit, too. Helped by a push from Boing Boing, it’s gathered more than two million views in the last week.

And, as Ad Age’s Michael Learmonth points out, it’s also an ad, paid for by Red Bull.

That won’t be entirely clear to most viewers, since the words “Red Bull” don’t show up until the end of the seven-minute-plus clip. And also because the folks at Google’s YouTube have plastered the video with overlay ads for products that are not Red Bull’s.

But the Red Bull people are apparently okay with that, since letting Google run an ad on your video is an opt-in decision.

CBS (CBS) says it will stop doing business with the ad networks, which are ubiquitous on the Web, and will offer access to its audience of 60 million unique visitors solely via its own salesforce.

AdAge’s Michael Learmonth says CBS, bolstered by its 2008 purchase of CNET, is the biggest publisher on the Web to cut off the hundreds of networks that try to match publishers and ad buyers.

Sounds right to me. Because while lots of people like to complain about ad networks, almost everyone uses them.

Other big publishers that have cut off ad networks entirely include Time Warner’s (TWX) Turner Networks, the Gawker Media blog network and…not many others.

The ad network debate in a nutshell: Anti-ad network types argue that handing over inventory to the networks gives publishers a short-term boost because it allows them to sell ads they wouldn’t move on their own. But doing so trains buyers to avoid buying higher-priced inventory from the publishers themselves, which means that stuff gets harder to sell in the long run.

The counterargument: What are you people smoking? Ad buyers should be trying to reach their target audience at the lowest possible price. And trying to fight that impulse is like fighting gravity.

Still, there is a larger movement afoot to try to at least sell some inventory at higher prices, even if that means leaving dollars (or pennies) on the table.

That’s one of the cornerstones of Aol CEO Tim Armstrong’s strategy, and it’s what Yahoo (YHOO) is trying to do as it reshapes its Right Media platform. See also: Firms like 5to1, which say they can turn publishers’ low-rent “remnant” ads into more valuable stuff.

The countermovement, though, is at least as strong, as ad buyers and brokers use technology to move more and more inventory at ever-more “efficient”–i.e., cheap–prices. See: Google’s (GOOG) relaunched DoubleClick exchange and the one that Microsoft (MSFT) intends to roll out next month.

In the meantime, Hulu wants us to know that:

• It’s now the biggest video site that isn’t Google’s (GOOG) YouTube, at least according to one count. Nielsen’s VideoCensus pegs the site’s February traffic at 309 million video views, which puts it ahead of News Corp.’s MySpace and Yahoo (YHOO). But as AdAge’s Michael Learmonth notes, it’s still not on the same playing field as YouTube, which generated 5.2 billion views during the same period.
• It’s not just a video site, it’s a social network. Or at least, it now has some social-network-like features, like the ability to share favorite clips with your pals. TV.com, Sling.com, Joost, et al, do something similar. The good news is that Hulu lets you import connections from Facebook, MySpace, Google, etc. The bad news is that this won’t appease broadcast and cable TV executives who worry that Hulu takes eyeballs away from their offerings, despite what someone told The Wall Street Journal today.
• Hulu users really, really like their “Saturday Night Live.” The show’s clips accounted for nine of the ten most emailed clips in the last year and eight of the ten most viewed videos that were embedded in other sites. Like this one.

Apple (AAPL), Research In Motion (RIMM) and Google (GOOG) are duking it out for consumers’ smartphone dollars this fall. But here’s an early winner: Time Warner’s (TWX) AOL, which has just landed a giant contract to push Google’s G1 phone for the next two days.

Wireless carrier T-Mobile, which is selling the phone in the U.S., is launching a big push on AOL’s Platform A ad network today. It has agreed to buy a billion impressions today and tomorrow, reports AdAge.

Reporter Michael Learmonth talks to industry sources who think the buy could cost T-Mobile around $1.5 million, which would work out to a cost per thousand of $1.50. Ad folks I talk to think that number sounds high, and guesstimate that the CPM will be closer to the $1 to $1.10 range.

But no matter what the number is, the campaign will be a win for AOL. Anything approaching $1 million over two days will be well-received at the company, which saw ad revenues drop six percent in the last quarter.

And the fact that AOL can offer an advertiser a billion impressions in two days also points out how the ad network business is supposed to work: Gather lots of Web sites and offer their combined inventory to advertisers, who can buy a lot of eyeballs at a discount. Now AOL just needs a lot more of these, fast.