Ask HN: Send a subscription invoice?

Since a lot of people here are running or developing a subscription business I thought I'd see what people think about sending out a monthly subscription invoice via email. 37Signals products send one out while other services like Netflix don't (I believe).

On one hand, having a record of when your credit card is billed can be handy. On other hand, each time you send this out it's a reminder to someone that they are being billed and my guess is that it will increase your cancellation rate.

I think it's always best to err on the side of what's best for your users which would point to doing it the 37Signals way but I'm wondering if there are any empirical findings about what's best here.