I think Ted has a valid concern about the 'free' level, there has to be sufficient incentive to pay something, and voting rights may not be enough. I also think that people bring much more attention and commitment to things they pay for, so just boosting numbers with 'free' level people may not mean much more than padding. That said, I think it is probably a good tool for raising awareness, future recruitment, giving access to lower income people, and building a "membership" base that will look big enough to impress politicians and others.
On tiered pricing, I think it is best to set an individual and household price as Patrick describes. Membership levels above that are really a fundraising exercise so you are "selling" t-shirts, etc.
I would propose something like:
Free - you get newsletter, can view the forum, but cannot post or comment. (Facility for a 'free' member to become a full voting member by engaging in a minimal volunteer activity. This should weed out any ringers, but allow for participation for people who care but really can't afford it.)
$12 - Student, senior? (verification or trust?)
$20 - individual membership
$40 - household membership (should this be double the individual price or slight 'discount', i.e. $35 since it's often two people. Look at what other groups do...)
$65 - "Activist", "Change Maker", etc. Household membership + one schwag item
$100 - "Kingmaker", "power behind the throne", etc. Household membership + two schwag
$500 - "Founder". Lifetime membership? (In fundraising it is common to have a listed amount higher than you expect anyone to pay. It makes the other levels appear cheaper and encourages sign-ups above the minimum level. And if someone does actually pay it...great!)
Separate note that we want to collect voting status (registered or not) as people sign up and location/district. I think most pols know that raw numbers like "X people on our mailing list" don't mean much, but if we can say "X registered voters, Y in your district" we will get taken much more seriously. (Assuming those numbers are high enough of course.)
All my categories and numbers, of course, subject to best practices of other established organizations...
Thanks,
Dave Matsu