- These numbers are meaningless, and are simply blows in the search engine war, far too reminiscent of the mid-90s war. Google won the war by proving it was relevancy that mattered, not numbers. Yahoo is doing a good job fighting Google, but this fight is just on the wrong turf.
You want to help people find what they need. The only way increasing index size would do that is if there's many cases where the index is missing an item that should be at the top of the search results. More likely is that most useful items are already in the index but just aren't being surfaced. In that case, the focus should be on relevance rank.
Update: Gary Price notes that "publicly announced pages totals can be useful but are often nothing more than a marketing tool" and that "relevant results are what counts."
Update: Jeremy taunts Google for having an out-of-date image index and boasts about Yahoo's 1B images.