Question
It seems that support for a marketplace could be consider a competitive advantage if it's tightly integrated into the transaction, so should this be built in house, or use a 3rd party app to do this.
What do AirBNB, Fivver, Thumbtack use?
Answer
Zendesk is one of the preferred systems being used by many marketplace startups and other global brands including, say Slack. It is extensive and scalable as I have used it at advanced level.
The advantage with Zendesk is that you get an excellent support center too, for knowledgebase articles. See an example of KB that I have developed for KarmaCRM, at: http://support.karmacrm.com/hc/en-us/. See few more at: http://in23hours.com/
GrooveHQ is another good option, https://www.groovehq.com/
