I meant that it would have been useful to put that information on the poll on the site (although thanks, Wilf, that's interesting info!).
If, as a researcher, you're presenting data like this you very rarely present it absolutely but usually show it relative to some kind of norma/average. In that way you can show which differences are statistically significant.
And most researchers would kill for a sample size of around 5000! To reach that number of people via traditional quantitative research methods is hugely expensive..
But I think the fact that there is a perception that 5000 MNetters is a low number reflects the fact that, in reality, I would guess that although MN gets a huge number of hits each day/week/month, and has a huge number of people registered, there is actually only a hardcore of nutters regular posters.
And the thread probably wasn't up for long enough and didn't stand out from the other threads enough for less regular users to notice it. (And frankly, given how many people also confess to lurking, I would also imagine that very many people simply couldn't be bothered to fill it in or, worse, were suspicious as to MN's motives in looking for this information).