Perhaps not, but it makes a huge difference in communications.
I'm a writer, so admittedly I'm biased. But breakdowns in communication are the root of many ills.
On a forum, miscommunication leads to arguments/fighting/loss of community.
On a sales site, miscommunication leads to dissatisfied customers - those who thought they were buying a green flying widget only to discover it's a chartreuse glider widget aren't going to be happy.
In the real world, miscommunication can lead to war.
The ability to communicate effectively and efficiently is vital, to my way of thinking, even on the web.