Popular microblogging service Twitter earlier this week announced that it had reached agreements with Microsoft and Google to integrate users’ tweets into search results, creating a dramatically changed environment for search engine optimization (SEO).

The battling search giants will both have access to Twitter’s vast store of public data in real time, enabling Google and Bing users to track trends with a high degree of accuracy. AFP reports that, under the terms of a recently signed deal with Microsoft, Yahoo will also gain access to the real-time data.

Microsoft has signed an additional deal that will give Bing and, presumably, Yahoo access to user status updates on Facebook. This will provide search engine optimization (SEO) professionals with an additional analysis tool to help them more carefully craft site content for improved search rankings.

Rumors about the Twitter deal had circulated for weeks, fed by sources inside that company who said that a deal was close. Experts say that effective search engine optimization (SEO) will have to become more responsive and more content-based in order to fully take advantage of the new opportunity.