2 years ago, when ethereum was the new hot sh*t. I started to build an Dapp (decentralized application). A big problem I had was to find the right database and after re-implementing the dapp with 3 different ones (pouchdb, gundb, nedb) I finally started to develop my own one, based on the best previous solution (pouchdb). It turned out that developing that single database was giving more fun and value to myself than any other software-project I had done before.

Like you said, everyone has a reason to do what he does, and so my reason is self-promo to be honest. I actually think most OSS-Projects are done by their maintainers for this reason.

For promotion I had done/do the following:

- Post on relevant subreddits

- Google for new results (last 24h) that match some keywords ("js database") and answer there if possible

- Posted it on Lobsters and other js-news-sites

- Shown HN (I did this a bit too much which maybe can be called spam by some or "growth hacking" by others)

- Currently I think about doing an egghead.io-tutorial for the project

I would say that overall I spend about 20% of the time for marketing, 20% for the code, 30% for the tests and 30% for the documentation. Most of the time I just code for some weeks and after a new release, I do some promotion.

Here is the project btw: https://github.com/pubkey/rxdb