To me, the word community connotes a separate entity that you interact with in some way, usually due to proximity. You might define the Craigslist Community as

To me, the word community connotes a separate entity that you interact with in some way, usually due to proximity. You might define the Craigslist Community as only people visiting craiglist.com but to me it would imply sites such as Padmapper that extend and improve Craigslist data. They are symbiotic and support the same community of users, Padmapper is not "repackaging" Craigslist like some sort of parasite like you imply. Anecdotally, whenever I've used Padmapper to find a new apartment I would end up on craiglist.com anyway as Padmapper would often not contain the real estate agent's contact information.