England 2018 launched the second phase of its digital campaign, created by Engine's Jam, this week.
Football fans on Facebook are being targeting through a peer-to-peer recruitment drive that has attracted more than 300,000 fans from 170 countries since launching in May.
Christian Lindman, Jam's social media planner, said the importance of attracting more fans was to make commercial sponsors feel that the bid's social media sites were valuable places for them to communicate their involvement direct to fans.
Jo Vertigan, England 2018 head of digital, said: "Social media has been a key element of the England 2018 digital strategy, ensuring fans from over 175 countries can find out about the bid, get involved and show their support."
England 2018 will discover if they have won the bid in Zurich on 2 December.