For me, Facebook is primarily a way to stay in touch with friends, family, former co-workers, that sort of thing. It is especially useful with people who live far away and friends who have less free time since they moved into the young-children phase of life. I check it a few times a day. I also post my planned bike rides there so that people will know where to tell the police to look if I disappear.
Twitter is primarily for news and entertainment, and I check it often because I find it very useful. I follow a bunch of local weather people, as well as a few who cover the area where my parents live. I also follow some reporters/columnists from the Washington Post (my local newspaper) and a news blog for Arlington County, where I live. Also some official county accounts for Arlington and Fairfax (where I work). Twitter has actually become my first source of news -- when a big storm is coming or something big happens, I hear about it first on Twitter. It's also a good way for me to follow sports that don't get much attention in the US, like cycling and Formula 1, and in fact I first signed up for it in order to follow cycling. And it's a good way to follow sports teams from major US sports (like baseball) that are based in other cities (Let's go Mets!) and the college teams that my nephews play for. I also follow a few comedians on Twitter for entertainment.
Last year a few relatives signed up for Twitter, and we use it as a kind of enhanced text message service. It's easier to communicate with a group on Twitter than via texting, as long as you're discussing things that don't require a higher level of privacy.
I have also set up a couple of lists of Twitter accounts that I don't follow but would like to access easily sometimes, such as local traffic reports and a longer list of weather people for the area where my parents live. I use the latter when major storms are in their forecast so I can monitor the situation.
I don't use Instagram. I have a Linked In account as a way of being able to stay in touch with former co-workers, though I don't do much with it.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles