There was a time when U.S. businesses could choose whether multicultural marketing was something they wanted to budget for. Is it worth devoting precious time and resources just to reach niche markets? Don't general-market campaigns already appeal to audiences of every stripe? And do these audiences even represent enough buying power to warrant targeted outreach?

If you're still asking those questions today, you might want to check out the results of the 2010 Census. Hispanics now make up 16 percent of the population, African Americans account for 13 percent, and Asian Americans 5 percent. Even more striking, every ethnic group experienced double-digit population growth in the past decade, with Asian Americans leading the way (43 percent growth). In four states, including California and Texas, non-Hispanic whites are no longer the majority.

Taken together, the buying power of the Hispanic, African American, Asian, and Native American communities now exceeds $1.5 trillion a year, according to the Selig Center for Economic Growth. "There are now 50 million Hispanics in this country, and if you look at the Asian American population, it's the same today as the Hispanic population was 10 years ago," says Luisa Acosta-Franco, vice president of multicultural marketing at Farmers Insurance. "As we see these shifts in population, any business – any marketer– needs to be serious about [reaching these diverse audiences]."