Agreed. And, Chipin is developing integration to these systems. Their technology is entirely xml based so the integrations are quite easy. Salesforce.com will have our first few clients up on an early trial of just such an integration. That said, salesforce.com is not the best example here as we don't provide public pages like Convio and Kintera.
So, a chipin masshup with these tools would be great!
Another way to look at this is to use Facebook profiles for the user pages. Chipin has a good Facebook integration.
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