The whole title sounds a bit weird. What about "Kayak for childrens' camps and activities" or instead of Kayak, Hipmunk? Since they are in YC, they should totally mention that in the title as well.
I like OpenTable for kids camps! I think more people probably get how OpenTable becomes a core part of the restaurant's infrastructure than Expedia does for travel.
we use the Open Table reference for our similar service I agree that is the closest comparison especially because I noticed you also have SaaS for vendors in addition to the marketplace.