Promoting newsletter sponsorships as a vehicle for side project growth is a great idea. I think using an email newsletter itself is not the right format but looking forward to a searchable database.
The searchable database is the real product, but to protect myself from procrastinating on this I forced myself to launch quickly. Hence the v0.5 solution.
So awesome. I was about to say the same about the searchable database, but I love this launch quickly / minimal viable approach. (I think I remember your previous iteration.) Still eager to follow this one!