It has been said that people buy for two primary reasons -- to solve a problem and/or to feel good about what they are buying. That truth stuck with me after hearing it described many years ago by Michael LeBoeuf, one of the first business authors to focus on customer loyalty.
There's a practical and an emotional side to most purchases -- an outcome desired by the buyer, but also some level of trust or satisfaction sought from the seller or the brand. Learning those desired outcomes and feelings is the challenge for salespeople and marketers. It requires some background research and questions asked to decision makers and product users during the marketing and selling processes.
Once you know what customers are really seeking, you can craft your value proposition. Make sure to address what's really in it for them -- how your solution will pay off and benefit the buyers in a way they don't have a ready substitute for. And get beyond the practical side to the more emotional undercurrents of what the purchase could mean. One of the most classical B2B value propositions was in the day of mainframe computers when people said, "Nobody will ever get fired for buying IBM."