"When a customer makes a decision, that decision represents the culmination of a cognitive process. It may take place almost instantaneously or stretch out over a long period of time, but it’s a process, not an event. Persuasive architecture weaves the buying process into the selling process. AIDAS [AIDA stands for awareness, interest, desire, and action (we add satisfaction)] provides the momentum to propel visitors through the site to a confirmation page."
I’ve always claimed that information architecture (applied to commercial sites) is marketing. I’m glad to see people such as the Adaptive Path team grow in influence over other professionals focused only on usability or information retrieval. Nobody but web professionals is in the business of usable web sites, and most companies are not in the library business either.
Don’t mistake means with ends. Usability or ease of use are means to reach an end, and if you’re a commercial site, that goal is to sell (even good customer support works towards that end.) Of course you want to gather user requirements, listening to customers and figuring out what they want is what business is all about. But a well thought-out information architecture and a usable design are just means to reach that goal.
It’s the "no parking, no business" of the online world. I don’t care that much about how the parking and store aisles you’re building for me are great by construction standards. What I want to know is how they help build the flow from just passing by to browsing to taking the product and looking at it to actually buying it. User Interface Engineering is another firm going in the right direction in the IA field (see for instance the "Are the Product Lists on Your Site Reducing Sales?" whitepaper).