contagion

To sell a lot of whatever you are making, the product itself has to be effective,
simple, and focused. In the words of innovation legend Peter Drucker, “It
should do only one thing, otherwise it confuses. If it is not simple, it won’t
work.”
In launching something new, the key word is “contagion.” That is, once
people hear about it or use it, they can’t stop telling others about it and this
creates “buzz.” But to reach your largest potential market, you must lower
the barriers to entry