How do you go about knowing when to move on from an offer you are promoting. I just ran my first ad and out of 220 clicks I got 3 opt ins and no sales. Is there a certain formula anyone uses that tells you to just cut your losses and find another offer?
This is a very tough decision and requires a lot careful consideration. There are many moving parts to a campaign including the traffic source, the ads, the landing pages, the offers, the placements, the audience etc...
If you are certain you tested all of those pieces carefully, and its just not converting it may be time to consider a different offer, but in your case there just is not enough info to give you REALLY GOOD ANSWER.
For example, without knowing the traffic source and offer style its hard to know if 3 opt ins is worth trying to optimize.