That's actually very interesting - what you're proposing is that to create a viral effect you don't send the same joke to everyone but tailor it algorithmically

That's actually very interesting - what you're proposing is that to create a viral effect you don't send the same joke to everyone but tailor it algorithmically to suit each recipient based on his history or some other parameter. The trick, of course, is being able to gather and mine the data needed to do so. It seems that facebook, Google, and a lot of other successful companies are following this model.