I recently started using Facebook a couple times a week, largely because there are a few people I care about who use only Facebook. Here’s the difference between the two social networks.
Facebook has accumulated and kept so many people for so long due to simple human inertia. Most humans are averse to spending time and effort to move to a new experience or platform unless there’s great reward and little risk in doing so. Facebook spends a huge amount of time and money, including employing many scientists, specifically to determine and maintain a balance where the pain of using Facebook is less than the pain of leaving it. The reward for using Facebook is the ability to connect with friends, play mindless games, and be served information you want.
Looking at Google Plus, it’s clear that not only would you have to rebuild your social network essentially from scratch, leaving behind many friends who are kept on another network by their own inertia, but you’ll have to learn a potentially more complex system, all without guaranteed reward. Google Plus also requires more effort to experience its potential rewards than Facebook. With Facebook, you can be mostly a passive consumer of information and services and experience much of what it has to offer. With Google Plus, you need to be more active in seeking out worthwhile sources of information and interactions. There are far more deep and intellectually challenging conversations to be had on Google Plus, but participating in them requires significant effort and many people aren’t interested in those conversations, especially at the cost of expending that effort.