@michaeljja not really an answer on a per campaign order rate, but make sure you have flows setup to remind people to purchase again, or upgrade (not sure what the product is, so what you think it appropriate). Although you aren’t getting high conversion rates, based on annual frequency of purchasing, I think your emails are still great for brand awareness and reminders. 

Also look at referral programs to help build your list and market to new, potential customers.

Yeah that’s a good point. Maybe one based on the estimated next order date (which always seems off in my experience but I guess it has the data for a reason), or a post-purchase flow for later down the track. I think you’re definitely right re the brand awareness, just hard to quantify how valuable that is.

Thanks a lot!