Yeah, I suggest you don't. They suck. Your budget will go up in less than a day or two. Second you will get a lot , yes a lot of clicks, but one this for sure those clicks will be 95 percent FRAUD. Waste of time, money. I would use 7 search before them if I had to use a 3rd tier engine.
I have used Goclick and had pretty good success with them but would have to agree that they haven't produced for me lately. If you decide to give them a try be sure to budget your money or like Amazan says, you'll go through your funds quickly.