I imagine that using semantic web approaches, some of the real social scenarios can be the following :
- I want to eat tonight, but I do not want to cook. I check on an aggregator what info has been posted locally , by whom ( with what credibility and reputation ), and what food is proposed.
I notice my neighbor plans to cook some nice libanese vegan food. I want to join him/her at his/her table ( if s/he made this option available ), or I want to simply order a portion , so that my neighbor knows s/he can prepare some more.
I can contribute to the expenses, or even allow a profit for my neighbor, or my neighbor may have chosen to give it - it depends on the information available.
The next day, I want to cook, and want to invite some people - and leave the option open, letting people interested contacting me.
Reputation can be used, and even special "meal credits" can be used / a mutual credit system.