Understand business before you try to consult

I have been speaking to a few people lately on how they deliver consulting services for SEO and Marketing to distribution businesses and it strikes me how little they know about the reality of running a business in the physical world.

I was talking to someone about how the increase in orders we generated from the web would affect the logistics workflow they currently had.
“Shall we suggest they look towards pick by line rather than pick by order as they are now?”

I think if you are in the business of telling companies what to do it seems to me that you need to know their business pretty well first otherwise how can you provide them advice that will have the best effect?