For the first few times, they would be very responsive and professional, when you trusted them and started having a lot of money in your publisher account, they will STOP paying and not response to any messages or emails!!! Just stay away from them. Checkout these screenshots: Meloads review Meloads scam Meloads cheaters
I have no ideas but think they use Google Adsense to re-advertising, so they didn't track clicks or CTR, etc. Btw, it also proofs that they are a scammer.
It happened to me too. 2 months they did not pay me $ 200. They do not even respond to the email or the support page on their site. Avoid them because they are scammers.
They begged me to try them out with a promise that they will pay per request. And yes, they did pay for the first few times, when I trusted them and having quite lot of money in my account, they started to scam...