Some products allow anyone to become an artist and tap into the human desire to create art. Products that enable this desire can have a tremendous adoption curve. Pinterest, Instagram, and Tumblr are all examples of this phenomenon. I think the ability to turn anyone into an artist is (part of) what creates a religious fanaticism in each product’s users.
With a few re-pins, you can create collections on par with any magazine. Or with a few taps, you can create pictures that look as though they should be in a museum. The beauty of lowering the friction to being an artist is that as the community gets bigger, it actually gets better! This is the opposite of most communities — think about Yahoo Answers today.
Pinterest and Instagram are not frivolous. They are the most efficient tools ever invented to create art. And creating art (just like sharing and connecting with our clans) is one of our most basic desires. Companies that own this behavior online are worth A LOT of money.