I'm not sure that it would be possible to mystery shop anything beyond the user experience for the website itself (and I did that as a usability tester for a company I occasionally do usability testing for). The reason is that unlike a fast food chain, grocery store, bank or other type of business where stores/branch have standards that employees are trained (usually) to meet, there is not a whole heck of a lot that's consistent about airbnb hosts. Having actually used airbnb, I've found that the reviews have been generally accurate for the hosts.
The only situation I can think of in which doing a mystery shop might be useful is if airbnb has some reason to suspect that something shady is going on with a host. Even then, the site has a mechanism for reporting problems.
On the other hand, if airbnb decided to do mystery shopping, I'd give it a shot if the pay was worth the effort.
Edited 1 time(s). Last edit at 08/11/2015 09:17PM by nutmegstategirl.