Conor Friedersdorf asks a great question: How long will you (and others) be using Facebook?

Imagine 7 years spent living in a college dorm, or 15 years spent attending the parties you went to in your twenties. Now imagine yourself perusing a Facebook stream daily for a full 25 years.

Doesn’t that just feel like too long?

I wonder how many of you will agree. It’s impossible to say right now. The popularity of Facebook among older people today doesn’t really tell us much. Like everyone already grown up when social media came along, they experienced the addicting novelty of remaking long-lost, far-flung connections while in between tasks at work or waiting for the onions to caramelize. People who grew up with social media all along will experience it differently in middle age.

A colleague with whom I spoke about this topic guessed that the middle-aged will stick around as users for nostalgic reasons, their accounts, full of archived photographs, serving the same function as old high school yearbooks. Perhaps so. But how often do you look at your high school yearbook?

Yeah, but your high school yearbook doesn’t talk back to you, or update itself. Conor adds, “Older folks might also stick around to lurk on the pages of their grown children, especially when grandchildren arrive.” I think that’s going to be big. America is a more mobile society than it ever has been, and that’s not likely to change. People will continue to move far away from their families, and may be increasingly likely to live in several different cities, even several different parts of the country, in the course of their lives. Facebook (or something like it) will enable them to maintain some semblance of affectional continuity.

In fact, I wonder if digital means of staying in touch — not just Facebook but all the social media — will make it still easier for people to uproot. I’ve heard people say that they don’t get together for dinner or drinks for friends as much as they used to because they stay in touch so regularly on Facebook and Twitter that it seems unnecessary. People who live two miles from one another could end up two thousand miles apart without any evident change in their relationship.