I was wondering, are networks like Zeropark, Popads or Exoclick adsense safe to give it a try on arbitrage? Or will you get lots of bot traffic that will generate a chunk of invalid traffic?
Adsense specifically forbids their ad zones to be placed in POP windows. So by buying POP traffic, you are effectively breaking this rule and you will get banned if they find out. The same goes for adult traffic, thats a no-no again.
I don't mean placing adsense blocks there. What I mean is buying pop traffic to redirect it to a landing page where people can have a preview of my articles (eg. a headline, photo and click here) and if they do click they go to my website.
You'll get banned. For a few years I had Adsense at the bottom of a thank you page on a lead gen site (so the user only saw the ads after filling out and submitting a form). Can't remember the eCPM but it was very high as the ads were in the finance niche and laser targeted. Traffic was a mix of tier 1 PPC and some PPV, policy changed a while back though and they don't tolerate it anymore.
He is probably trying to do Pop to Adsense arbitrage.
I would be personally careful with AdSense as Google is pretty sensitive to these things.
Doing it the way you described -> so that AdSense is 1-click away could be quite safe, but the risk is still pretty high and I think Google is now smart enough and will automatically lower your eCPM when they detect such schemes.
A few months back, I was chatting with a good friend who's a rep on a big pop traffic network, about this topic.
She told me that there were a lot of people still making insane amounts of money doing arbitrage.
However, doing this with Adsense is risky - as has been pointed out several times.
Having said that - adsense is not the only contextual ads program available. 
Amy
I burned through about 8 Adsense accounts trying this "1-click away" approach. Adsense revenue was showing 10x ROI from pop traffic, but none of it was ever paid before accounts were shut down.
The problem is the insane amount of bot traffic that is present on pop networks. Heat maps of subsequent click patterns confirmed this. I implemented lots of programming tweaks to try to filter it out, but it doesn't take much of it to corrupt an Adsense account.
I would suggest trying other contextual ads programs. Another approach I've had success with is bleeding some traffic to Adsense pages from existing Adwords promotions for related offers.
That is actually a good tip vortex. I did have a lot of success in the past with fb ads and adsense, till I was banned.
Care to share which combination of traffic source + contextual advertising might work?
I think AdSense arbitrage is something that worked 10-15 years ago.
They employ the smartest engineers in world, I wouldn't mess with them at all these days.
Rather look for other networks or checkout native arbitrage which is more relevant to these days.
Anyways, traffic arbitrage will be around as long as there are people on the internet and with so many networks around new loopholes may come up at any time.
Good luck!