I agree there's few if any examples of more recent entities. I also am pretty unfamiliar with actual numbers of active users per se, though. Tumblr may be the c

I agree there's few if any examples of more recent entities. I also am pretty unfamiliar with actual numbers of active users per se, though. Tumblr may be the closest, maybe Quora although I'm not sure even Quora compares to Reddit. Maybe Snapchat? Flickr? Probably not; I'm not sure about those for several reasons. I think there might be some kind of memory bias in the sense that we're less likely to remember things that have receded into the background or even disappeared but I agree that as more users come on board because of network effects it's harder to let go of a service or to replace what it has to offer.