I come across this most often when looking for technical manuals. Some sites lie to Google and other search engines about having a large selection. You arrive full of expectation only to find they don't have what you needed, or even anything of interest at all!
I think they fib because they get paid per page view by their advertisers. It pays to lure people on to an advertising site. And not bothering to provide any genuine content is cheap – no research, editorial or copyright fees. Money for nothing;. Not exactly fake, but certainly not honest either. Time-wasters.
Dave