In episode 141 of Semantic Mastery's weekly Hump Day Hangouts, one participant asked whether one should pursue an alpha campaign in Google Adwords if no conversions have been made yet.
The exact question was:
3) My home building campaign is getting to the point where I'm identifying the keywords that I will use for an alpha campaign. (one even has 8 out of 31 clicks). I plan to start an alpha campaign in few more days, but should I do so if I don't have conversions yet?