Well at least it didn't cost you anything.

Here's another way to look at it. How many times has someone rang you up about advertising and siad we do this local mag/paper/whatever and you can advertise in ther for only £50 and you think well go on worth a try. You do that and you get ....... nothing, but you gave it a try.
Now do the same with Adwords and you get ....... nothing or do you? Even if you get no calls you have collected data. It is this data that is the starting point to creating a return on investment.
Who is succesful with Adwords? The person who is prepared to pick over the results. Do you know what split testing is? Have you heard of peel and stick? These are the things you need to spend time on to really find out if it's a goer or not.