Paid advertising has been the talking point of most articles that you find on the Microsoft Yahoo deal but you don’t see a lot of talk about the impact that it could have on SEO.

The most obvious impact is that if you are optimizing for Bing you are also optimizing for Yahoo. All of your current rankings on Bing should show up on Yahoo. Of course, this isn’t anything that’s new for SEO. Google listings currently show up on AOL. Also, your title’s and descriptions will show up in Yahoo as they do in Bing.

SEO’s shouldn’t see any difference as far as robots.txt and XML Sitemap files are concerned.  The search engines came together on these some time ago. The biggest issue, though, might involve Site Explorer. Site Explorer is one of the most reliable tools for competitive backlink research. It allows you to see a list of links to any site and will rank the links in order of value. Currently on Bing and Google you can only see the backlinks for your site. Since Microsoft at one point removed the ability to query index data for competitive research, it seems unlikely that they would take over the Site Explorer feature.

Ultimately, though, it’s going to come down to what type of traffic you get from the two sites. Depending on what report you believe, Microsoft Yahoo will have between 25 and 28% of the market share. That’s a significant amount of traffic for sure, but there is still a ways to go to even be in Google’s league.

For more information on what impact this has on Web Developers, visit Search Engine Land