Lavalounge.com needed a powerful scaleable store that was supportable by someone who would answer the phone when questions needed to be asked. Not to bad mouth other store providers, but they dont have a handle on their product and cannot support smaller clients.
OS Commerce supports an integrated administrative area that allows the store owner to print shipping labels, invoice electronically and track inventory. It also allows for multiple sixe, color or style vairiations on a single item. This is significant in that it allows for multiple inventories on single items.