Since we were discussing possible acquisition targets for Berkshire a thread or two ago, Strava might be worth a mention here. Sequoia was one of the early VC investors, IIRC. If it goes public soon, as rumored, the price might be nonsensical, but Berkshire can be patient. And there are some baked-in advantages worth noting.

For those who might be unfamiliar, Strava is essentially social media for (mostly endurance) athletes. Distance running can be proverbially lonely, and Strava provides a way to see what your friends are up to, encourage them, compete with them if that's your thing. A fair number of pros are on it too, which is kind of cool (and very humbling). The network effect is powerful: people who are on it have an interest in common, and they put a lot of time into that interest. The degree of specialization means there isn't really a competitor. I have to think the number of users will hit a hard ceiling at some point, but I think that's OK.

There's a free tier and a subscription tier. I'm cheap, so I'm on the free tier, but I've thought about it.

In addition to being a social space, Strava also serves as a training record, from daily efforts to races. In that regard, it's extremely sticky, like Facebook back when it was more a photo album of your friends' kids and weddings than... whatever it is now. Data can be set up to upload automatically from most athletic trackers (Garmin, Coros, Apple watches) so you may have years of data to look at. Not that the data doesn't live anywhere else, but it's kind of a nice archive.

Strava already does lots of tie-ins: shoe companies, companies that do nutrition, etc. To avoid this becoming a bunch of pushy, intrusive, ads, they offer 'challenges' -- complete X number of days of your activity and you'll be entered to win some performance sugar goo. If sugar goo doesn't sound particularly appealing, competitive runners and cyclists have an absolutely insatiable appetite for goos, gels, bars, and powders. Some will spend a lot of money on that stuff. Others are value investors.