- if we are going to use channel advisor is the multi-store upgrade necessary?
Not necessarily - Channeladvisor can deal with multiple seperate instances of ADNSF - however - this will obviously mean multiple ADNSF licences.
- can anyone who has experience with channel advisor explain
------ how the integration with ASPDNSF works (how easy is it, what level of technical knowledge does it require, etc)
Pretty much no work for you - Channeladvisor have already done the integration work. they use ADNSFs webservices
------ how the integration with Ebay & Amazon works
Channeladvisor provide a central platform which 'pushes' inventory/listings/products out to the various channels - ADNSF, eBay, Amazon
------ does it matter if ASPDNSF has been modified (ours is a UK store)
Strictly speaking - they don't permit midifications - it causes nightmares when it comes to upgrades etc, however, talk to them - they may be wiling to give a little.
------ are the costs levied by Channel Advisor worth it?
Probably - you'd need to consider if you could replicate the service they're providing & if so - what would it cost you.
THanks