Some of my Christmas shopping included trying to evaluate some items via the Web. The purchases were just large enough to justify trying to read some reviews and pick the "best" rated item. But I found the effort trying at best.
We have all been bombarded with these "work from home" advertisements. Many of these schemes involve setting up link farms peppered with (mostly) Google ads and a few links to legitimate sites. Enough people have bought into this scam to the point that they are now cluttering up search engine results. And based on my experience, I actually think the search engines are promoting the rank of these sites precisely because they carry ads. So the effect is that legitimate sites that carry genuinely useful information are crowded out by link farm sites with useless information, a few mostly useless links, and lots of ads.
Search engines are not a free service. We pay by giving up some of our privacy, and we pay by clicking on ads. Search engines still deliver good value, but they may be debasing their own currency.