Advertising Age is reporting an imminent deal between Microsoft and Yahoo, part of which would probably involve making Microsoft's Bing the default search engine for Yahoo. There are many implications for many people in this deal, but let's look at some basic ones for search engine marketers.
First and foremost, marketers will see changing traffic patterns in their web sites. All of the search engines rank sites differently for various keywords. Therefore, when the deal goes through, Yahoo's old rankings will change to be in line with Bing's rankings. This means that if you had a great position in Yahoo and a poorer one in Bing, your position will drop and your search traffic will probably reflect that. (And conversely, if Bing ranked you better, your traffic will be better off.)
Likewise, if you have a paid search program that is designed to complement your rankings in organic search (e.g., buying ads where your organic ranking is not high enough), then the foundation on which you made your decisions might change overnight. You might be buying ads for keywords where you now have high rankings or not buying ads for keywords where you now rank poorly.
As marketers, and especially as agencies overseeing our clients' marketing efforts, we should all start reviewing our current metrics and our strategies and tactics based on those metrics to see what we need to change. At Domus, we pride ourselves at being a very nimble advertising agency, and as such are already starting our reviews. Are you?