If you advertise on Yahoo!, you’ve probably received their notices about the upcoming merger with Bing. This is going to affect how your ads are displayed and you need to modify your ads accordingly:
While Yahoo! has a 40 character title limit, ad titles in adCenter may be no more than 25 characters. In addition, Yahoo! ad descriptions may be up to 71 characters, versus 70 characters with adCenter. To prevent your ads from being truncated in a way that may cause them to read improperly, or be ineligible for display, please revise your ad text now. Doing so now also gives you plenty of time to test ad copy variations within the new character limits.
Search engines will also be merged, from what I’ve read and this means whereas Bing & Yahoo! separately were not a large enough component of total searches to worry about, they will probably account for 25-35% of all searches in the future. Their algorithms (how they decide who ranks highest) are very different from Google’s.
Once they’ve merged their engines, I’ll be spending time analyzing search results to see what they are considering important. If you’re a management client, that may mean some adjustments to your site to make sure you rank well in Bing/Yahoo! as well as Google.