Kodah,
Boy, once you got that AMA dictionary you got dangerous!
I can speak from my own experience only, of course. It's been um, quite a few years let's say, since I took consultative sales training, but here goes.
I think the threads you'll find running through all those definitions are: expertise, customer needs and solutions. The AMA throws in a taste of integrity, too.
Probably examples would be the best way to describe how I understand the concept.
There are 2 salesmen in a used car lot. The owner is trying to move an SUV, and is giving a big bonus to the salesman who sells it. (Please interpret salesman as a gender-neutral term). A little old lady arrives to look at the cars. The first salesman walks her over to the SUV and talks to her about what a great deal the car is, how much safer she'd be in a big car, how much room she'd have for her grandchildren, etc. He puts a big rush to get her to make a buy that day - before the price goes up. This is not the consultative salesman. He doesn't really care about the customer's needs, he isn't worried about finding a transportation solution that fits her lifestyle.
The 2nd salesman sees the old woman after she has shooed the first guy away. (She probably would have left the lot, but for the sake of the example..) He starts a conversation with her about her transportation needs - he discovers that she's an old maid with no children, who lives alone, only goes to church on Sundays, has a bad hip, and a low budget. Looking over the inventory, he discovers that the only car on the lot that fits her budget is a stick shift. He also knows that Harry's Used Cars down the street just made a deal on a nice little car in her price range that is reliable, is an automatic shift, and gets great gas mileage. He suggests that she drop into Harry's and gives her the year, make and color of the car she should look at.
Yup, you got it. Salesman #2 is the consultative salesman. Did he lose a potential sale? Yes. Did he make salesman of the month for the next 3 months based on sales to people who were referred to him by the little old lady? You bet. Did salesman #1 quit 2 months later? Yes -- he hadn't been able to sell anything to anyone because the little old lady is the sister of the mayor of the small town, and she really black-balled him.
The only dispute I have with one of Google's definitions is that the sale must be complex. I think you can be a consultative sales person no matter what you're selling.
Hope that helps.
Kathleen