Having enjoyed my free month, I just signed up for the monthly plan (I don't own a Bellicon but, rather, a competing manufacturer's product).  One thing I wished was made clear before taking the plunge was the terms of cancellation.  It turns out the monthly subscription can be cancelled at any time online (which is fantastic, BTW), however, making this clear to potential subscribers ahead of time might help people make the decision to join or not.  Many monthly online subscriptions are a monumental PITA to cancel, which makes people very reluctant to sign up.  Making it clear that you can cancel at any time - with a simple click online - may help alleviate concerns, and boost monthly subscriptions (and perhaps retention rates as well).  

Cheers!