While adsense pays .5 cents, CPM ad pay anywhere between $6 to $50 per 1000 impressions. It is quite popular among the large ad spenders and top 1000 brands
This is simply incorrect.
AdSense pays a lot more than .5 cents CPM, even a lot more than 5 cents CPM in many sectors, niches and situations. I don't know any of -- repeat, any -- ad network that pays anything even remotely approaching "$6 to $50" CPM for display ads.