Twitter is complicated enough to explain with just one feature. If they launched with more I'm not sure the behavior for which it is now famous would have come

Twitter is complicated enough to explain with just one feature. If they launched with more I'm not sure the behavior for which it is now famous would have come into existance. We've had to change the feature we've had front and center once we discovered friends were having trouble explaining it to one another. Part of it is just a marketing problem -- you need something to be naturally expressed in a short period of time.