Traditional brand building and advertising are still needed, but the execution has changed. You still need to define and communicate the difference and reason to choose your brand. But repetition in massmedia just does not work solely anymore as means to create attention and interest towards your brand.
How can you ensure the customer experience will meet the given brand promise throughout the whole purchase journey? This is a big operational and communicative challenge to all companies. Over promise may bring new customers but bad experience will certainly not bring them back. And the word of mouth spreads in seconds, all over the world.