Google's search competition is not simply confined to the other big two players - it comes in all shapes and sizes, according to The Motley Fool.
When it comes to making online publishers money, Google would be wise to remember that it's not just competing against Microsoft and Yahoo, the Fool writes. It also needs to keep its eye on Amazon, which runs its Affliates program as a way for publishers to make commission fees on business they send Amazon's way. It also recently unveiled its Clickriver cost-per-click product that allows advertisers to put ads on Amazon pages. And it now has a contextual-marketing product that its affiliates to opt into.

But Amazon isn't the only company in Google's rear-view mirror. Miva runs a contextual advetising program that, while nowhere near the scale of Google's or Yahoo's, still have a sizable publisher base.

The point is that Google might not have to worry about large intrusions to its revenue stream, but there is the potential that it could suffer death by a thousand small cuts.