There's bound to be a small amount of memory used by the idle crawler, but if they designed it well, it seems unlikely that that would be a limiting factor. Yo

There's bound to be a small amount of memory used by the idle crawler, but if they designed it well, it seems unlikely that that would be a limiting factor. You make a fair point about the AdSense. I would guess they care more about a better user experience, but it's certainly possible. Everything they do can be viewed as a means to keep people searching and using the web, and clicking on more ads.