I know this is anecdotal but i don't find their findings to be true in practice -- at least as far as facebook.<p>If facebook tells me I got 180 clicks, my javascript detects 100 page views, and 45 people fill out my form, then I know at least 25% of those clicks were real people, or bot sophisticated and motivated enough to actually continue through filling out a form on the destination page.<p>There is certainly click fraud on every platform -- clicks that only facebook/linkedin/google report, but never appear on server logs.<p>I'd be interested in knowing what your personal experience has been, I know there are many people on hacker news who've advertised something in the past.