[rallison]

The main reason that this TLD has recently gained traction is due to google adding .io to their generic country code top level domain (gccTLD) list:

https://support.google.com/webmasters/bin/answer.py?hl=en&#3...

[josteink]

Not entirely accurate.

That all happened after hipsters squatting these domains cried Google a whaaambulance over not getting the search-rank they felt they "deserved".

Something else made these utterly pointless domains popular before that, but what that was, I don't know.

[kybernetyk]

> Something else made these utterly pointless domains popular before that, but what that was, I don't know.

Possibly 'io' being short for input/output. The first .io domains I remember were some programmer blogs/personal sites. Now they are just over used.