Does Google Adsense pay the highest when it comes to per impression basis? What are some good alternatives that I should explore? Thanks.
Yes i do think when adsense pays per impression basis they are the best - but not always as this is keywords and site depended. Hope it helps...
If you want to earn more from pay per impression basics put your adcode both text and images on high paying niche like health,insurance like that
There's no rate, the eCPM will depend on your site's topic, your ad placement (CTR) and your source of traffic, if it is highly targeted and there are ads, people will click often and so your CPM will increase.