This winter I discovered MegaPush as a great source of high quality push traffic. The prices for some countries were really cheap and good to start. I converted AV offers and Sweeps for EU countries with a ROI above 30%.
Right now the situation has changed. I have started a raw campaign with all feeds and ROI around -30% which is excellent for the start and can easily go positive after feed optimization. And it actually did after I removed all feeds with negative ROI.