I must say, if you want to build something that instantly has a market consider building plugins for existing 3rd party systems that allow you to charge a fee. It ends up being a much smaller project than trying to build your own, huge web app, and it comes with a targeted, focused audience who can easily install your app with a couple clicks (and get charged). You don't really have to market anything.
Build something good and people will find it.
I know a few companies and people who make good money with shopify-, wordpress- or atlassian-plugins.
There should be a directory for such systems with market places.
6 days ago: https://news.ycombinator.com/item?id=14708201
9 months ago: https://news.ycombinator.com/item?id=12670731
2 years ago: https://news.ycombinator.com/item?id=9423592
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It has been a free service for many years but now there is a premium HD version.
GPU's are used for mining other cryptocurrencies like Litecoin and Ethereum. These can be traded for Bitcoin or fiat currencies.
