You're not making any sense. They can shard the hell out of their indexes since all searches are user specific, so that's a non-issue. They can afford to throw enough hardware at the problem if their business model works out and they attract enough paying users. It's presumably not cost effective for Google to offer a super snappy search experience through gigabytes of user-specific data, which is why Gmail search sucks so badly for people like me. (Does anyone know if search is way better if you're a paying customer of Google Apps?)