When a person or business sends a message to a network of people this generates an exponential process that can consume considerable amounts of resources - most importantly human time. This can have a beneficial effect on those interested in the message, but can also consume time of people not interested in the message. It can also create in many a social obligation to look - albeit briefly - at the message - particularly when it is from someone you know or consider to be a friend.

When a message is completely unwanted and unsolicited, this is a form of information pollution and is often known as spam. When a message is from a network of friends, and wanted by some but not all, it generates negative externalities in that it consumes valuable resources (time).

Some examples : Bill sends an email or social message to 20 friends. Of these 2 are very interested, 8 become interested, the rest aren't interested but may read all or part of the message anyway, spending their time. Some of these 20 people will forward the message to their friends. The process repeats - resulting in an exponentially increasing consumption of time by those uninterested in the message (as well as an exponentially increasing consumption of time by people who are or become interested - which may distract them from other more productive tasks). Eventually, when the expected number of people forwarding a message drops below 1, the process dies out, but in the interim it may circulate widely - resulting in a potentially massive waste of resources. Much of the time wasted will be due to a sense of social obligation to at least scan or check on the title of the message.