Just how important is it for brands to pay attention to Millennial consumers?

Just how important is it for brands to pay attention to Millennial consumers? Today, Millennial spending power is estimated to be $600 billion; in 2020 it will have risen to over $1.4 trillion, surpassing the spending power of Boomers, and at that point Millennials will make up 75% of the workforce in the U.S. (Daily Finance)