[brudgers]

From a content standpoint, StackOverflow requires the participation of domain experts to be successful. Facebook just requires people to sign up and log in.

[Tyrannosaurs]

That doesn't make it more complex, it just means that it has a very specific requirement for the knowledge of the participants.

From a software perspective it's really no harder to gather and store 1000 words on a detailed C++ problem than it is to gather and store "Mmm mmm mmm, Justin Bieber, he's soooo dreamy".

[brudgers]

The "just" in:

"it just means that it has a very specific requirement for the knowledge of the participants,"

is not a trivial exercise that should be left to the reader.

The technical issue for Stackoverflow is to make editing an standards enforcement efficient and socially desirable to a highly tech savvy community.

It's not storage, it's filtering.