I think this has been brought up before but I'll start fresh here...
After visiting a site via a G ad - ads from that advertiser follow me for days - even weeks. How smart is that?
Before I tender MY opinion on this, I'd like to point out that without any data on how successful this strategy is, all I have to offer is simply that: opinion based on my own nature.
That said, I do see and click on ads from time to time. Often enough, this occurs because the ad sparked my interest in a product or service. However, once I visit the site and get the information I require, I don't need to see any more ads for this product/service. I know where to go if I decide to buy. So further advertising is not only counterproductive, but it also gets downright annoying.
At this point, I've distanced myself enough from ppc to be out of the loop so I don't know who pays for these ads. It would be interesting to see what ROI they get from this.
I may well be the exception, but I have a feeling that most advertisers will soon modify or drop this strategy after the novelty.