Woah, this is weird. Twitter has apparently starting promoting Firefox 3.5, which was released last week, to some of its users. Judging by Twitter Search, the banner began popping up around eight hours ago, and given how few people have tweeted about them it seems like they’re not being very widely distributed.
The amusing thing about the banner is that Twitter’s site may not be properly detecting which browser their visitors are currently using — Chris Saad, who tipped us off to the annoucement, says he was using Firefox 3.5 already. That said, most of the other tweets about the banner do appear to be showing up to users who aren’t using the latest version of the browser.
At this point it isn’t clear if this is a sponsored ad or more of a public service announcement. Update: It isn’t an ad, see below. If it’s the former, it would be a significant departure from the more subtle advertising Twitter has been toying with over the last few months, which has primarily consisted of small text blurbs in the right sidebar of the site. Twitter only recently began charging for some of these ads (or at least presenting them as sponsored links), and most of them are still free promotions for apps and services in the Twitter ecosystem.
Even if this is a public service announcement, you can be sure that Twitter is closely monitoring the banner’s performance in anticipation of placing full fledged paid advertising there. They really wouldn’t be any more intrusive than the vast majority of banner ads on the web, but after years of going without any advertising at all, they’re going to take some getting used to.
Update: Twitter co-founder Biz Stone has gotten back to us with details on the company’s motivation for placing the banner:
This is not an advertisement and it’s not just for one browser—it’s customized based on which browser you’re currently using.
We’ve optimized Twitter.com for older browsers but we thought it would be worthwhile to let folks know that they could have a better Web experience on Twitter and in general if they upgrade to a newer version of whatever browser it is that they are using.