What's the absolute worst conversion rate I should allow?
 

Example:
If I'm buying short text links (ex: "Ass Pics & Movies") and offer 24 hour free trials with credit card or check, what's the worst conversion ratio I should allow before spending money elsewhere?

How much do the text links cost? Its something you would base off the ROI I suppose..

conversion ratios has always seemed like a shitty method to gauge anything to me, the bottom line is what matters most.

worst ive experienced is 1:500

how much do you get per sale and how much do you pay for the link, it's pretty easy to see if it's making profit or not