It seems to me that these two are complements.  Search is outward facing and community is inward.  Search is many many short transactional relationships, like shopping, while community is deeper longer transactions – i.e. real relations.  That Google is a search company and Yahoo is a community company.  Even Facebook, for all it’s flaws, is a community company.

Advertising is more at home in a searching context, and less so in a community context.

Huh?  I don’t seem to have told the whispering hammer story.

As the marginal cost of goods decline there is some threshold where advertising can pay.  Information goods, who’s marginal cost approaches zero, are the most common commodity paid for with advertising.  But my barber gives away cheap combs, address books, key chains, credit card magnifiers, and a half dozen other things.  His phone number is printed on them.  I picked up the bag I carry my computer around in at an Apache Software Foundation conference some years ago.  It was paid for by advertisers.  I will note in passing that I carry both my barber’s comb and ASF bag because of my enthusiasm.

So the question arises why advertising doesn’t appear in some venues where the marginal costs are extremely low.  For example why did Eudora’s Ad supported email client fail? Why doesn’t Microsoft sell a discounted version of Word that features embedded advertisements.  I think the reason is because people find it extremely irritating to have their concentration interrupted by their tools.  Advertising is intolerable when in the flow of real work.

My summary of this insight was a joke.  Presumably the marginal cost of a hammer is really quite low.  Not much higher than a plastic comb.  So someday soon we should see the whispering hammer.  As you lift it to strike the nail it would whisper advertisements for band aids and stainless steel nails into your ear.

Well, so it maybe that search v.s. community is one of those complementary balances that shakes out with one side being commoditized while the other garnering all the profits.  I don’t know.  But commerce does have a significant corrosive effect on community and this appears to be more of the same.