The OP has shared a simple offline method, even if he exaggerated the numbers it's still feasible. THINK PEOPLE. Crowds attending concerts are HIGHLY TARGETED PEOPLE, THEY PAID ($20-$200) FOR A CONCERT TICKET, THEY LOVE THEIR BAND,TEAM,etc. AND WILL DEFINATELY VISIT a website thanking them and giving them a "FREE" gift, if they fill out 3 input fields. There's nothing not to believe about this, #2 the OP said he was placing these on cars, How long would it take you to lift up a windshield wiper and place a flyer there? How much time do you need to do that 3 minutes? 4 minutes or a couple of seconds? The conversion rates will definately be off the roof because like I mentioned earlier. THIS IS HIGHLY TARGETED TRAFFIC. The only way you can screw this up is by having a weak ass landing page, and weak ass Adcopy on your flyer. BONUS: Another way you can ensure that people visit the site is by placing a code on the flyer ex.CBEFG and on the flyer tell people that 20 Lucky event goers will win back the cost of the admission. They must visit the website fill out the cpa offer, then enter the flyer code to see if they 'WON'!....Make sure your webhost can handle the traffic you will be getting.