Annual dues vs. anniversary dues
I served as director of membership for several years at a couple of different associations. When talking with my fellow association membership pros, the question often arose: Which is best; anniversary dues or annual dues?
Some quick definitions: anniversary dues are dues that are renewed a year after the member joins (e.g., I join in May, I renew the next May), while annual dues renew at the same time each year (e.g., all members renew in January).
So which is best? Here's my general rule of thumb (keeping in mind these are rules of thumb; they are not absolute, and there are certainly exceptions):
If you're an individual membership organization (IMO), anniversary dues are best. If you're a "trade" association (i.e., organizationally-based members), annual dues are best.
Anniversary dues are like subscriptions. Buy it today, it expires a year from now. Most adults understand this, and thus explaining it is easy. In addition, IMO dues tend to be relatively low-cost (i.e., typically under $1,000) and usually a single person is making the decision about joining/renewing. So all around, it's just easier to say "Join today, renew a year from now."
By contrast, trade association dues tend to be much higher priced, and often require multiple individuals to make the decision to join/renew. And very often dues are a budget item, which means budget cycles will drive decisions. And so very often, the annual dues renewal period is set to coincide with the "typical" budget cycle of the members. For example, trade associations for schools (high school and college) often have renewals in August or September, because that's when the new budget year begins for many schools.
Like I said above, there are certainly exceptions to these rules, but in general I've found that anniversary dues are best for IMOs and annual dues are best for trades.