I have this same question. I usually do the same thing. Post on reddit a few times, ShowHN, product hunt etc. I got lucky and one of my side projects, deckofcardsapi.com, really took off because of HN, but I haven't been able to replicate it.
Here is my feedback, hope it helps you.
First off, instead of showing off an api calls & response, show a use case. Make a simple site that utilises the API, then in the details page show the calls & response. Don't make api details your whole site.
I am someone that plays cards with my friends and I didn't understand the use case of the API.
API is the backend that you developed for some reason. Its nice you are sharing it. Show the reason. So that other can addon or make their own spin. Make a demo project using the API.
I had 2 "successes" 5 years apart. Most recently, ProductHunt got me 30K views in one day on this site, http://lowpolygonart.com/ and I think the backlinks that I got as a result have carried the site for a couple years, but any of the other projects I've released have been dead on arrival.