You basically have to say, everyone from the CEO/CFO, to the auditors, the financial analysts, the legal team, and all the way down are all lying and this random guy on Twitter is telling the truth. Sorry, not buying it.
Most people don't know this, but the Search Advertising auction is a black box. The advertiser just specifies a bid (the maximum they're willing to pay for a click); and the search engine promises that they will not pay more than that.
Here's a trick that Search Engines may (or may not, I plead the Fifth) use: the price an advertiser "i" who bid "bid_i" pays is bid_(i+1) * pctr_(i+1) / pctr_i where "pctr_(i+1)" is the predicted probability of click (pCTR) on the next lower ad; "pctr_i" is the predicted probability of click on the current ad.
Guess who calculates the pCTR? The Engine! In theory, if their pCTR calculations were 100% accurate, all advertisers would pay the minimum bid (which is typically $0.01)! Clearly, this is not desirable. So Engines juice the revenue by tweaking these pCTR values. Talk to anybody who works on auction mechanisms at a search engine, and you'll hear stories of how they tweaked these pCTR values.
And given all the replies to that post on Twitter, it sounds like it's true.