I think you did get useful data:

Spent two thousand dollars on adwords and got zero sign ups

With that, now you have to figure out why. There are two paths to explore:

1) Your product doesn't meet the needs of the market. It's not useful/valuable. 2) Your messaging doesn't properly communicate the value of your product to the market. So they couldn't understand why they'd need/want it and left.

Figure out which one of those is the case (could be both!) and keep marching.