No longer just a marketing and sales tool, it has become what Dave Allen of WPP's brand and identity consultancy Sampson Tyrrell Enterprise calls the "central organisational thought" of many successful businesses.
But for the idea of the "brand promise" permeating the whole organisation to work, there has to be much better communication between functions. It is no good for a car maker to launch an advertising campaign lauding the quality of its products if customer experience is known to fall short of that mark.
Mr Allen, European chief executive of the consultancy that this week renames itself Enterprise IG as part of a drive to create a single world brand within WPP, does not claim that his view is new: others also talk of brand "integrity" and "reputation". But he says there is a danger of such concepts being used superficially by over-eager marketing departments. Firms need to realise that brand development must be taken seriously in all parts and at all levels.
He draws an analogy with information technology in the 1970s and 1980s. Until the personal computer IT was largely the preserve of IT departments. Then IT became part of the whole business, and specialists were no longer the sole experts.
"We're attempting to do for the brand what systems integration did for IT," he says. His firm, employing about 350 people around the world, is starting to take on people with backgrounds in such areas as finance and IT as well as the more usual design and related fields "to help make the connection and drive it into the fabric of the organisation".
With clients such as BP, Rolls-Royce, American Express, Coca-Cola and Safeway, he and his colleagues feel they are well placed to convince doubters that sustainable success in a changing and competitive market will depend on strong brand values.
His pitch comes as a new book, Competing on Value: bridging the gap between brand and customer value, makes much the same point. Simon Knox of Cranfield School of Management and Stan Maklan of Computer Sciences Corporation, the authors, argue that the Unique Selling Proposition once central to marketing has passed its sell-by date. In its place will be the Unique Organisation Value Proposition - a method of defining and delivering the customer value, which is now the key to branding.