burcot - 10:02 pm on Oct 25, 2010 (gmt 0)
I suppose it depends on your niche, but, I don't see many commercial sites with any helpful technical information.
Delivery time scale - People that bought this widget, also bought - The best returns policy in the universe - - Fifteen people rated this product with an average 5 stars...etc
I suspect you are going the extra mile and including useful information. eg. This widget will only work above atmospheric pressure. For best results please see our detailed user information guide. Download installation pdf here.
The downside (comparing to own sites) you probably rank for a lot of phrases starting with "how"
Amazon would never admit to ranking for anything that started with "how"