A non-negligible portion of the bot networks are teenagers and college students learning how to manipulate the system. Inexperienced operators like that make a

A non-negligible portion of the bot networks are teenagers and college students learning how to manipulate the system. Inexperienced operators like that make amateur mistakes like leaving in default user-agent strings for a variety of tools that are frequently linux-based as its cheap to go on something like LowEndTalk.com, pick up a couple $2/month VMs, pick up some proxies, and test out a small group of bots designed to fake traffic to generate Ad revenue. The reason I said teenagers & students is you have to be really, really sophisticated for that sort of operation to scale beyond $100/month in profit so its generally something I've seen people "learn" on, realize the limitations, and move on. (i.e. Making no amateur mistakes that flag your traffic as non-legit and being able to use an IP address only a couple of times a day in random patterns)