Statistics provided by Yandex blogs blogs.yandex.ru
What matters most in creating a community. Right. Find as many like-minded people as possible. Here I will try on the example of 3 services to show how the possibility of adding participants is presented in them.
I'll start with mail.ru
I have been using communities on mail.ru for a long time. I am sure that there is nothing like this on the Internet. Just look at the statistics of the Yandex blogs

A word to say on this list at one time shook the LJ community but ... even the cats ousted them.
')
You can invite anyone obsalyutno to the community on mail.ru, taking advantage of his interests. There is no such thing on more than one service. Verified

Somewhere once for 20 people the inscription will appear with the input of numbers, but this is insignificant. You can click on two, three, five inscriptions "call" at once, and the request is processed without refreshing the page.
But in LJ, you can send invitations through this form.

Those. you need to first find people by interest, and then painstakingly copy them to NIKI in this window. Note that you can only enter 5 users at a time. After clicking save the procedure will need to be repeated again.
Go ahead.
Ya.ru

An attempt to create a community was crowned with failure. Do I have any lack of KU?
Ok, I thought, I’ll find a community with very few people, join and try to promote it ... and ...

Join the lovers of mountain bikes and photos ...
But where is the button to call the community? Rather to the club. Of course, it may appear later. But here's another joke - It turned out that I can't write in the club until I have ... horror ... 20 ku!

In addition, Mene was offered to leave the club))
So my advice to you. If you want to organize a community, use mail.ru communities.