Since the official implementation of the Microsoft/Yahoo! deal is still several months away, it remains to be seen precisely what impact this partnership may ultimately have on search engine optimization. However, there is no mistaking the importance of two key areas of focus:
1) Optimizing for Microsoft's new BING search engine.
Under the terms of their 10-year partnership, all searches conducted on Yahoo! will be powered by BING, which is Microsoft's new and improved search engine launched in June. Yahoo! already accounts for 20 percent of online searches so that combined with Microsoft's 8.4 percent means this partnership should enable them dominate close to 30 percent of online search traffic. Granted it's far from the 65 percent that Google commands, but still significant.
2) Exploring pay-per-click (PPC) advertising opportunities.
In exchange for using BING as its go-to search engine, Yahoo! will receive 88 percent of the revenue from search ads for the first half of this 10-year deal. Emphasis on the PPC program is expected to increase the importance of supplementing Google PPC with Yahoo! PPC too.
Yahoo! is also expected to strengthen its content offerings. Presumably this will serve to attract more visitors and, in turn, increase the importance of seeing your site listed in Yahoo!/Bing's organic and paid search listings.