You forgot Tipjoy (W08) and Snapjoy (S11).
Another thing YC companies love is using "hello@" for their contact email address.
Another thing YC companies love is using "hello@" for their contact email address.
"joy" is a three letter word that is incredibly positive.
To come up with the name, I wrote down every word that was about money and payment, and every one about happiness, and tipjoy was the shortest combo. I bought it for $8.
The reason you see so many now is that these characteristics haven't changed.