Thats why you niche down that is select a sub niche of the broader niche so you can be reached by that segment of traffic and even many others. And thats why your reviews should be good or useful because there's a lot of crap also on google and sometimes people do not really take time to search too much.

Hey Robert,

Google only recently got into becoming an affiliate marketer too, so you bet that Google could be your greatest competition. However, so far Google is only doing affiliate marketing for the most popular products out there.

So, if you provide helpful information that ranks well in search results, your visitors could see an offer in your sidebar... or check out the link you provide to your landing page and if they are happy with your information shared, then you may even find them happy to trust your product link(s).

Hope you find this helpful.