though they are a bit late to introduce their coin but don't forget the fact that they have many users in this platform. adoption of their coin would be fast and easy because it encompasses a large part of the community at all levels, rich or poor, all types of individuals, different races and so on. if the fb dev team will make their cryptocurrency easily understood as like an idiot-friendly coin, then the adoption will spread like wildfire. many people are still ignorant how to deal with crypto so creating this fb coin might gain more ordinary users and educate them how crypto coin works.
The Facebook strategy is indeed quite good, with so many communities it is not difficult for the development of FBcoin. Even though there are many investors who are not interested, there will be a lot of migrants who are more curious and will contribute in it. The success of FBcoin will occur but I don't think it will beat Bitcoin.