I have approximately 1000 current members (5000 total in the database who have signed up, but we recently upgraded the site and are moving members over to the new one individually as they re-sign up). As for income, between membership purchases and donations, I have taken the following figures directly from my finance manger in the admin panel:

Calculations for the query

Membership subscriptions $8557.51
Donations $6069.02
Contact sales $0.00
Events tickets $0.00
see more Total $14636.53

As you can see, we've received almost as much in donations as we have in memberships, and this is due primarily to the dedication of our members. We've spent a LOT of time and effort on establishing a good relationship with and between our membership, and it has paid off nicely in the support we receive from them.

Subscribing is just a modified version of the normal process. The only difference is that the member pays for their membership up front now.