I think it's "undecidable" because we'll never know how many do it but don't get caught.
The only thing I can say is I hope most get caught. But they're just wasting their time trying to fake value while they could be creating more value for themselves and others.
That would only indicate my own skill or lack thereof at it (btw I think I'd be hopelessly clueless at doing it). You couldn't meaningfully generalize to the whole population.
Such as improving the product so more people want it. Sounds like they employ people who aren't doing anything productive and have to dream up crap like this.
Strictly speaking in terms of effectiveness, your #2 point is most often very wrong. You could be giving out free bars of gold and not have one customer speak positively of your service unless you really prod them.
People are EXTREMELY resistant to becoming advertising tools for corporations.