African-Americans use the most voice minutes — on average more than 1,300 a month. Hispanics are the next most talkative group, chatting an average of 826 minutes a month. Even Asians/Pacific Islanders, with 692 average monthly minutes, talk more than Whites, who use roughly 647 voice minutes a month.

The same pattern applies to text messaging, with the average African-American sending and receiving 780 texts a month, Hispanics 767, and whites 566. Of course, the figures for all three groups pale in comparison to the 2,779 SMS messages sent or received by the average teen each month.

Location also appears to play a role in mobile usage, with the South showing the greatest use of voice minutes. Texting appears to be more popular in the Midwest.

The Nielsen numbers, which are compiled from the actual mobile phone bills of 60,000 U.S. subscribers, point to a continued need to focus on mobile content delivery beyond apps and Web-enabled smart phones.