What both sides are actually buying
A multi-year contract is an exchange of certainty. The customer gives up flexibility and receives price protection and usually a discount. The supplier gives up the chance to reprice and receives committed revenue and fewer opportunities for the customer to leave. Both of those are real and neither is free, which is why the negotiation should be about what is traded rather than only about the headline rate.
The common failure is that only one side of the trade is documented. The discount appears in the price schedule, and the certainty the customer thought they were buying, a lock on rates for the seats they expect to add, an exit if service collapses, turns out not to be written anywhere.
