Sure, but presentation is everything, especially when using dark patterns. What's the subject line, a general marketing slug like, "What's New at...", with a little bit about points or whatever at the end of the email, or something more specific to the nature of the subscription?

What's the probability that the customer is unaware that this is a "membership" email rather a monthly email sent because you signed up and bought once? It's not uncommon for Newegg or Amazon to send you emails.