What do you mean by "mindshare"? It's not like there is any real community on those sites. For me most of them are completely interchangeable. The only exception is Gist, which has the advantage of version control.
Lots of people (that I know, anyway) know what Pastebin is, and don't know of any of the other, similar sites. If they need to paste some output, they type "pastebin.com" into their address bar and that's it.
