What I did..
Search for an affiliate program or CPA offer that has a unique name and is searched over 1000 times a month (Google keyword tool)
use compete.com to see if the site is active over 3k visitors a month.
Make sure the offer allows PPC bidding on exact company/product name
sign up to promote.
Then promote on Bing Ads for keywords like:
product coupon etc
to figure out my max CPC bid i just divided my pay out by 100 so if I was to get $30 pay out my max bid would be $0.30 my thinking is that after 100 clicks at least 1 will convert and I at least break even.
Hope this helps someone I'm still learning but think I will be killing it in a few months with PPC its a lot less headache than marketing my own info products lol