Early feedback told me that 7 day trials were too short. Specifically, potential customers were concerned that 7 days wouldn't be enough time for them to run into job failures (that would trigger alerts) or to get an idea of what NotifyCore's logging and reporting capabilities are.
I've been trying to decide between making trials 14 days or adding a free tier. For now, I decided on the longer trial period since I'm not clear on my path to convert free tier customers to paid ones. I plan to experiment with the new trials and address the idea of a free tier in the future.