I'm not currently doing this myself so take what a say with a grain of salt. Anyway, here is a couple of things to consider when getting into traffic arbitrage:
1) Content. before you do anything else you want to make sure the the content on your page is interesting and adds some kind of value to viewers within your niche. Remember you're generally going to be buy traffic that is either untargeted or only targeted towards a broad niche. You want to catch people attention and keep them interested so they stay long enough on you page to actually click on some ads.
2) Quality of the traffic you buy. You need to ensure that the traffic you're getting is real. This is done in 2 steps: First you filter out all the obvious bot traffic suppliers. If a supplier is offering you niche targeted traffic at $10 per 10k page views you can be pretty sure that the traffic is not legit. The second step is testing. So you found a couple of suppliers that looking promising. Their prices are not ridiculously low and maybe you have found a couple of reviews of their services online that look promising as well. Now just setup your page with stat tracking and buy the cheapest package that the supplier offers. What was the bounce rate of the traffic? How did they interact with your site? Did they click around to view multiple pages? For how long did they stay on your site? Using all these factors you should be able to judge whether the traffic is real or not.
Test all your potential suppliers this way one at a time.
3) Experiment with ad placement. Look up some of the popular sites within the niche that you are targeting. How are they placing their ads? For starters, simply copy whatever ad placement they are implementing. Once the traffic starts coming in you can move some of the ads around and track of conversion rate changes.
4) A note about testing. Always remember to only test ONE THING AT A TIME. If you make multiple changes and then make a new test you won't be able to tel which change increased (or decreased) conversion rate etc.
Anyway, it's not a fully detailed guide but I hope I provided you with some starting pointers. Good luck with you project.
