(3) happening destroys Google's current business model. Google's entire operation is funded by increasing the amount of times users click on a link and leave.

(3) happening destroys Google's current business model. Google's entire operation is funded by increasing the amount of times users click on a link and leave. There's little value in simply showing an ad, all the value is in the conversion. Yes, Google is well positioned to destroy that conversion rate, but that comes at great harm to itself. Display ads go for 1/10 the price of a search ad, and I'd wager text would be worth even less than images, and I'd bet the tolerable amount of ads per query is significantly higher for search as well. Is Google willing to bet the house that (2) is a better business model than the clicking described in (3)?