This just came up in an IT buyer's community and I think it is really important:
IT Practitioners get their knowledge from IT peers, industry training, logic, math and experience. Same as any other technical pursuit like civil engineering.
IT Buyers should get their knowledge for IT Practitioners
IT Buyers who believe themselves to be IT practitioners use whitepapers - a quasi-technical sales tool that looks like technical advice but is actually vendor sales advice. Whitepaper is an IT industry term for a marketing brochure with technical information used to guide customers to what the vendor wants done - which is not necessarily bad, but is not the same thing as industry advice. The vendor's agenda is not the same as the customer's agenda in all cases. IT works for customers, whitepapers represent vendors.
Similarly, Gartner could be considered the same as whitepapers, without the technical benefits.