PPC Arbitrage?

I see a lot of news and article sites forsale. For instance one spends $70k a month on ads and returns $82k. Where are they finding traffic cheap enough to be able to make money via ads? What prices are they paying? Is it possible to but traffic on sites like Mgid.com for under 1 cent per click? Anywhere else?

1 cent clicks are garbage. You should play with Bing and AdWords

definitely high quality sources, cheap ones are bad, but this depends on the niche, can you give an exact example of such a site?

Not all cheap sources are bad, you need to find right ones . Don't burn of money with adwords, bing, mediabuy etc which are getting rigid with terms now, also they suspend you account in middle of campaigns
start by getting good cheap ones

I am working for some time in this niche and got good results. You could send me a PM and I can tell you some things.

You also have to remember that people spending $70k to earn $82k are playing a dangerous game they've likely played at smaller levels. If you can spend $7 and earn $8 congrats, but nobody is retiring. If you can spend $7 and earn $8k that's much better. With PPC it's often hard to scale above that and the people spending $70 are likely doing direct ads with sites rather than low quality 1 cent clicks. I know a guy who was doing a lot of low quality PPC spends but he couldn't scale because there weren't enough low quality clicks that would convert.

I've been doing the same thing for 6 months now. My best days, i'd break even (from bought traffic to converted onsite traffic with the Widgets). Im still looking for a good source of not-so-expensive CPC native traffic, to convert it with my widgets and other tools like you. It is, indeed, not an ease job as everybody will tell you. If you find some good sources, please share. So far, I've tested MGID (not that good), Content.ad (expensive, even though I have creatives with high CTRs, and Im buying Non commercial), Advertise.com (still expensive). Best shot so far: Facebook traffic, but you have to find content / articles that stick and make you lower your cpc. I've seen 0,02 cpc with my fb mobile traffic. Hope this helps.