Agreed. That's why it might make sense to fight NIH on the general problem of sending emails, but to give into NIH when deciding to use an "external service to handle email drip campaigns" vs. building it in-house. That type of problem is much more specific to your needs and attempting to outsource it could cost you more time and complexity than it saves.
Using an ESP for delivering email is a no brainer in most cases.
Looks nice! The design of the example PDF is a bit noisy for my taste (the geometric shapes at the bottom of every page). And the demo PDF you generate by uploading a markdown file has a lot of whitespace. But I assume that's all tweak-able with a real account.
I got an "Oh no! We hit a snag processing your report. Markdown help." error without telling me what was wrong with the file. Seems like images break it.
For making these kinds of PDF I currently do this: 1. Write version controlled rst/markdown/creole. 2. Convert to HTML with a small script / command line tool (which also lets me do pre- and post-processing, like adding CSS). 3. Use chrome's print dialog to save the page as a PDF. This works pretty well for me.
It's not on the list. The least expensive metros range from $0.50/sqft to $0.65/sqft and Detroit-Warren-Livonia, MI is $0.94/sqft. That metro area is larger than just the city of Detroit itself though, which is probably what you're curious about?