There are actually 2,700 registered members on SE23.com, but 122 people represents significantly more than the number of people who I see posting over a few months, I suspect it is a high proportion of the regular users.

There were 600 responses to the council consultation in the summer which had leaflets delivered to most houses in three wards (about 20,000 people I think). I think a survey of 100 people, with an overwhelming view, is a good guide for the mayor to the results on any additional consutlation he wishes to do over the next few months.