My Adf.ly Campaign Returns No Conversion in CPAGrip

Creating a campaign of an offer from CPAGrip with paid traffic from Adf.ly is my very first mistake ever in CPA Marketing. It returned no conversion after I invested $5 for 1000 visitors from USA to perform an action to get free Best Buy voucher.
Lesson Learned
Prior to creating a campaign in Adf.ly, I have reviewed an affiliate marketer's thread in IM forum who shared his story purchasing traffic from Adf.ly to promote an offer that returned negative ROI. However, I decided to purchase it although I did doubt it would generate leads, that usually visitors tend to ignore ad to get directly to the pointed URL.