[Zope] Personalization strategies. And just what does Broadvision do ?

[chas]

Just wondering if anyone has thought about personalization
services based on Zope ? 

The most obvious/traditional approach seems to be :
1. Acquire user information (via forms/surveys/transaction-histories etc)
   and store in RDB. 
2. When the user comes to the site (and either logs in or is identified 
   by IP or cookie), query the RDB for customized content or appropriate
   products. 

OK, no magic there. But it's not very scalable in terms of :
a) Load. We can keep shoving Zope servers on the front end
   but the RDB is going to get hammered if this has to occur
   for each and every request. 
b) Development. A more object-oriented approach would be nicer.
   eg. Personalities with behaviours and properties. 
   Could a pool of persistent personalities be left floating 
   around ? (No, this is not an early April's fool) 

A while back (1997) I saw Broadvision and didn't really appreciate
what they were doing. It seems that they've really improved a lot
since then but I can't get my hands on their software (not for free
anyway). So, I'm wondering if anybody has experience with it and 
can enlighten a heathen on key features we might wish to, er, 
'appropriate' in Zope systems ?  Or is it, like Vignette and Netscape
ECXpert, nothing special and you're basically paying for the 'knowhow' ? 

Thank you,

chas