Melanie Swan has a great overview article on the social and business trends that are creating what she is calling "Markets 2.0", and the core of her argument is the evolution of markets to a logic of affinity.

Here’s the introductory paragraph:

"The long tail, smart mobs and social networking are driving the evolution of economics to Markets 2.0. Social networks have been important venues for self-expression and interaction and now, with an increasingly linked online populace, are starting to add a new and important functionality, virtual aggregation for group power, both economic and political.

 Two key concepts in Markets 2.0 are Social Finance and Affinity Markets. Social Finance is the virtual aggregation of dozens, hundreds or millions of people for the purpose of conducting an economic transaction. Social Finance is also known as crowd funding and crowd sourcing.

 Affinity Markets are marketplaces where transactions can occur based on affinity attributes."

Now that the P2P Foundation Wiki is fully restored, though 3 weeks of updates have been lost, we are adding new entries again, with a lot of new business terms added, which you can find through the Recent Changes category.

The work of Melanie Swan has allowed us to create or update the following entries:

• Reputation-based Employment Marketplaces‎; Group Purchasing‎; P2P Donation Finance‎; Prediction Markets‎; P2P Finance‎; Affinity Investing‎; Affinity Markets‎; Social Finance‎;

We also recommend the older entry on Social Commerce

With the help of Francois Rey, we have developed a new typology of Peer to Peer Exchanges,

Here it is:

1. Buy/sell, e.g. classified listings of items on sale
2. Gift, e.g. Freecycle
3. Auction, e.g. eBay
4. Barter
5. Sharing, e.g. car-pooling/rideshare, book lending and exchange, time-share accommodations, etc.
6. Mutualization, e.g. mutual insurance
7. Group Purchasing, e.g. LetsBuyIt.com (a special case of mutualization)

See also

1. P2P Finance
2. P2P Donation Finance

Any help in developing/defining this typology and its individual elements would be much appreciated.