Each signatory is required to submit their email address and tick whether or not they wish to receive further communications from Nationwide.
Paul Hibbs, senior sponsorship manager, Nationwide, said: "The joint initiative is primarily a tool to get our association with football in people's minds. Email capture is secondary at the moment, but with a double opt-in process to go through it will certainly identify people who like football as well as Nationwide."
Last month the company signed a £40million deal to sponsor the football league, FA Cup as well as the England team up to the 2006 World Cup finals.
At the time of going to press, 121,000 people had submitted messages, of which 105,000 are full registrations.
"We will be interested in seeing how many of these are already customers,
said Hibbs, "and we won't rule out informing the others of our products and services."