Not only did GoDaddy initially support SOPA, they went so far as to send a letter to the House of Representatives committee debating the bill a letter describing it as "thoughtful and comprehensive." When faced with a mass transfer of domain names to other registrars initially organized on Reddit, GoDaddy slowly backed away from that stance.
Although GoDaddy claimed to have dropped support for SOPA on December 23, it wasn't until four days later they made it official by withdrawing their letter from the House Judiciary Committee and had their name removed from its list of supporters.
NameCheap's promotion, promised domain name transfers below cost on December 29 and a $1 donation to the EFF for each one. Even before yesterday's promotion, GoDaddy had lost tens of thousands of domains.
GoDaddy customer service put a lot of effort into convincing upset customers not to switch during that time, but for obvious reasons many people weren't persuaded.
When the total number of transfers yesterday topped 25,000 yesterday, NameCheap CEO Richard Kirkendall doubled their donation to $2 per transfer. The promotion was also extended another 12 hours, ending at noon today.
More than 32,000 domains were transferred from GoDaddy in that period. Of course that just counts domains transferred to NameCheap. Other registrars have not announced figures and right now only GoDaddy and ICANN (the Internet registration authority) have the full figures.
GoDaddy finds themselves in a difficult position right now because of their status as a major hosting provider and the top domain name registrar in the world. It's even understandable that they wouldn't want to make themselves an even bigger target in case SOPA, or the slightly less horrible Senate version called PIPA, becomes law.
Still, there's a wide gulf between staying silent to protect yourself and taking a position directly opposed to the interests of your customers. They likely haven't made too many new allies by appearing not to care what their customers think until it after it hit their wallets.
Their apparent tone deafness seems particularly bizarre in light of their own problems caused by being on the wrong side of intellectual property law abuse.