I have a business idea like every other week and I apply this quick 3 question test to see if I should spend more time research it or not.
1. Do I feel the pain of the problem myself?
2. Is this a universal problem?
3. Am I able to solve this problem?
Interested to see your versions of a litmus test. Would also be great to get feedback just in case I've missed an important question.
P.S I wrote more about my thinking at my blog pragmaticstartup.tumblr.com