This is definitely interesting. At 7% annualised, those $38K would deliver around $33M over 100 years. Keeping a simple website up for those kinds of gains seems like a no-brainer. Hosting is cheap. Especially as most of these are going to be very low-traffic personal websites serving mostly cached static pages.

It seems like the best way to guarantee that something runs for 100 years, actually; build an investment fund whose mandate is to keep some basic websites up on a couple cheap servers.

Edit: Even if technology changes, that's just a maintenance job every year - keeping the underlying infrastructure updated. Some years it will be cheap, some years it'll be a bit more costly, but ultimately it's not impossible at all, especially if they've got a big number of clients (and thus a big fund to draw from).