trafficvance is mainly game installs.. so user types will vary..
Those Trafficvance installs can often come via little kids downloading stuff on their adult relatives' computers, as well as bored and dumb adults installing them, so there's a variety of niches that can work there.
TV and 50onRed are serious companies (that take a little effort to get approved on), so they do have an incentive to work to reduce the number of bot impressions. Same goes for Leadimpact, theoretically, but they are trash for other reasons. DirectCPV and MediaTraffic are not serious companies, in my opinion, and bot traffic is written into their business model.
But I don't think you should be scared of some bot traffic in general. Every traffic source has plenty of it, and it's up to you to take steps to mitigate it through closely watching your traffic, performance and targeting when doing self-serve stuff.
I'd be more worried about news like this leading to the end of public PPV networks sooner than expected:
Adware: A new approach - Microsoft Malware Protection Center - Site Home - TechNet Blogs
I've done a lot of PPV across TV and LI in the last few years, and I really think anybody starting out should be working with niches and approaches that can be easily transferred to other kinds of display media, so you move on quickly once you're ready to scale past what PPV gives you.
When you want to scale, the amount of babysitting effort it takes to get there through PPV is extremely annoying. Add in the chance that the whole system could collapse or shut you out suddenly, and it really isn't worth it once you are ready to drive volume. At least that's how I see it, I'm sure there are plenty of people who disagree.