I get a few signups per week for check-run-reporter.com, but few folks actually end up trying to use the product (though nearly all those that do keep using it).
I think I could drastically boost my conversion rate if I could send just one or two emails to folks at the right times, but so far, I've been unable to find any affordable, functional solutions for sending automated not-quite-transactional-but-not-quite-marketing emails.
Does anyone have any recommendations?
I use ConvertKit for Indie Hackers and it works just fine. If you want a more programmatic solution, I also use Postmark, and it's great.
Sending the right emails at the right time is great, but I wouldn't count on it being a silver bullet. There are often lots of smaller, easier optimizations you can make to your website copy, messaging, signup flow, etc., that also pay dividends.
We use Mailchimp. I'm usually pretty surprised at how expensive it is though.
I would second what @csallen said: in our experience there are lots of smaller, easier optimizations you can make that will pay dividends.