My site already has a Facebook authentication feature, allowing people to login using their Facebook accounts. Works perfectly, for certain people who have FB accounts. Is it a good practice to provide only FB authentication option? What are the pros and cons?
Actually, I need to convince my customer that FB login is enough, and we don’t need any additional “login forms”. Would be nice to show him some articles/researches that prove my point of view.
Piggyback authentication is a growing trend among web applications. It really depends on who your audience is. For example, if your web application is related to open source projects, it would be quite reasonable to require users to use Github authentication.
If your service’s primary function relies on Facebook integration, I would say yes it’s okay to only have FB auth. However, if it’s just an “option” like linking your profile to your well FB profile, then having a primary custom login would be the best idea.