Also as a side note, thank you for daterangepicker! I've integrated it into a couple little things I've built like chrome extensions and absolutely love it.
* Improvely got its first customers from Google ads. Because Improvely has a high CLV (customer lifetime value), I could spend a lot on advertising to acquire a customer and still make money from it. So that's what I did. Once I had a couple dozen customers, who were all delighted with the product and the support, word of mouth started taking over. These days 90% of new signups are referrals from an existing/past customer, or referrals from some website that's written an article or review mentioning Improvely. I still run some Google ads but with a limited budget.
* The open source projects get their traffic from Stack Overflow, forums, people searching NPM and other repositories, etc. The Date Range Picker widget got its initial traffic from a "Show HN" post I did here.
https://news.ycombinator.com/item?id=4408070
I've started other SaaS apps that never worked out. The thing that made them different from Improvely and W3Counter is that nobody was super excited about them. Nobody loved those products; they were maybe useful but not the best at anything and not particularly unique. So the word of mouth referrals never came, churn was high, and eventually I shut them down and tried something else.
We need more stories and details about such endeavors, but unfortunately most don't write about it.
Btw, how do you monetize the Date Range Picker?
The AdSense ad on the documentation website
It gets quite a bit of traffic -- https://www.w3counter.com/stats/90840/dashboard
Yes, although this is irrelevant regarding monetization (with adsense).
- I have a couple open source projects, and hosted "webmaster tools" type projects, with one-page websites like http://www.daterangepicker.com that get ~10K visits/day, and run one AdSense ad on each page, which brings in a couple hundred dollars most months.
- I run a web store where I resell another company's products (with permission) targeted at a different customer group than their own website. I advertise it on Google AdWords and Bing Ads on just a handful of keywords. Fulfillment is automated through the other company, so I haven't touched the store except to update the design every few years, and it brings in $500-$1000/month in profit. Sorry, don't want to link to this one, too easy to copy.
- Dividends from stocks and high-dividend-yield index funds are totally passive. But first you have to earn and save the money to invest in them. I also have some money in REITs, investing in real estate without having to buy and manage the real estate.
- I used to run some referral ads on my sites for a merchant account provider I used 5-10 years ago. A couple businesses signed up through those links and still use that company for their credit card processing. The commission agreement was a lifetime residual based on their monthly processing volume... I'm still getting $100-200 transferred into my bank every month from that company even though I haven't been referring anyone to them for years.