Just had a very "interesting" chat with an ad-network based in South America. They contact me as they thought I had display advertising to sell them - in their words, they "can't get enough of it". I explained that actually we are a software company whose product detects fraud traffic, but they're more than welcome to use it. After all they don't want to be conned by their publishers surely? Their response - they don't care whether the traffic is genuine or fraud. That's someone else's problem! Actually I am surprised. Suspected this was their attitude, but to admit it?! Now I'm not suggest they're all like this, but just how widespread is the problem?
I am not surprised anymore. The INTERNET is filled with scammers and frauds. We just have to learn how to avoid them and the damage that they can cause. So, to answer to your question you have to be concerned, but not surprised.
I think u'lll find that the ad network in concern is probably some teenager working from his parents basement....lol He wants to make quick money and doesn't care if his publishers are quality ones or not....
..he's not, they're well known. There's always been problems with fraud traffic I know that - I had a large reputable network sell me 30%+ bot traffic, but this was the first time I've have them admit to me they don't care about fraud, even though the technology is available to stop it!