ePrize launched a user data verification service to help marketers validate the personal information that online visitors give them, according to ClickZ. The service, introduced in ePrize's own promotional give-away campaigns, compares data against known addresses and filters out known fakers by comparing against black lists and blocking certain IP addresses. ePrize said that about one in twenty online giveaways wind up being awarded to fraudulent entries, which denigrates marketers sense of value for the data collected in such efforts.