Twitter launched its first sponsored promotion on @earlybird today, the official e-commerce account that ReadWriteWeb first reported on earlier this month. Followers of the account got a link retweeted for buy one get one free tickets to Disney's new movie Sorcerer's Apprentice.

The contrast between this launch and the launch of Twitter's other new advertising product, sponsored trending topics, is remarkable. It seems to send a clear message about @earlybird promotions: They are for weaker products that can't handle the open public conversation of trending topics. That's ok, it's a good idea in fact - but that's what seems to be happening.

The first promotion that used sponsored trending topics was another Disney movie, Toy Story 3. When that promotion launched, we called it groundbreaking, because the promotional message appeared on a search result page side-by-side with whatever the public has to say about the product. Twitter explained that sponsored trends could only be purchased for subjects of existing widespread conversation among users. If a good number of people aren't already talking about something, Twitter won't sell you a conversation starter.

With @earlybird deals it's very different. And the choice of promotions seems symbolic.

Toy Story 3 is a really good movie. People were talking about it and saying very favorable things. I went to see it because Michael Moore said it was great - and it was.

Sorcerer's Apprentice is a bad movie. It got terrible reviews from top reviewers on Rotten Tomatoes.

It's not the kind of thing you'd promote by drawing peoples' attention to the public conversation about it. It's the kind of thing you'd promote by giving buy one get one free tickets to it.

It's a good idea for Twitter to offer both kinds of advertising: a new, social media option like trending topics and an old-fashioned push broadcasting option. There's a whole lot of money to be made in sponsored broadcasts on Twitter.

We've asked Twitter's communication team for its opinion about this theory and will update this post if we hear back.

Update: Twitter's Matt Graves wrote us in response to our inquiry and offered this: "We've gotten a lot of interest from advertisers in participating in the @earlybird program, which gives us the luxury of picking & choosing the types of deals we offer to @earlybird followers.

"Quite simply, we are choosing offers where people with a strong affinity for a product get a rare shot at a great deal, and where brands benefit from the social excitement & awareness around a great offer."

I think that means he doesn't agree with my theory.