Bots or not, this is not traffic you want. In addition to the suspiciously repetitive browsing and clicking behaviors Andrew described, you only have to do a quick look at your web logs to see that their user base consists mostly of old Windows XP machines running IE7 browsers. In fact, in the time period we monitored, less than 10% of the traffic was using a modern or non-Microsoft browser, with less than 1% using an Apple product. This is way off the demographics and proportions seen with organic traffic. Even if this wasn't suspicious in and of itself, is this the audience you want to target? In the end, none of the traffic converted and to ad insult to injury, Google withheld the bulk of ad revenues for that time period citing a sudden spike in bad traffic.