Chief Creative Officer and Director/Experience Designer Alex Lieu told IGN, “That was it. Literally, people just found these cards. They started taking pictures and posting them on boards. Digg was a really big thing at that time. There was no URL, nothing like that — but someone went to IBelieveInHarveyDentToo.com, and there was a picture of the same Harvey Dent poster that had been tagged by the Joker. And the website said, ‘Hey… if you want to make your vote really count, give me your e-mail.'”
Every email address unlocked a single pixel of the first image of Heath Ledger as the Joker.
Alex continued, “We never underestimate what happens when millions of people get together and try to solve something. It took 97,000 e-mails [to unlock the Heath Ledger Joker photo]. The first, like, 20,000 or 30,000 were immediate — and then it slowed down, and then people were trying to run scripts and stuff, which we blocked. So they had to Digg it, and go to all comic-book forums and movie forums to get enough people to crowdsource. During the 20 hours [it took to unlock the image], people were Photoshopping what they thought it was going to look like. And it was so incredibly accurate.”
Source: https://www.buzzfeed.com/kristenharris1/wild-movie-publicity-stunts
