If there is a point of digital saturation, American consumers certainly haven't found it yet. 

According to Nielsen's latest Digital Consumer Report, just about the only digital activity Americans don't do more of is watch TV live -- ie not recorded -- and sit at their desktop computers. Otherwise consumers are playing video games, watching DVDs and recorded shows and using smartphones more, more and more. 

The report attributes consumers' increasing content consumption to the sheer proliferation of digital devices; on average, Americans now own four devices each. Consequently they spend about 60 hours weekly accessing content across these devices. 

The results come from a number of Nielsen's studies and surveys conducted throughout 2013, which involved thousands of U.S. consumers. Among the report's other findings were: 

  • Of social media users, 64 percent visit a social media site at least once per day on their computer.
  • Almost half of smartphone users visit social networks on their devices daily.
  • And 84 percent of smartphone and tablet owners use these devices while they're watching TV.

Why are they looking at two screens at once? Consumers will often use their tablets to find information related to what they're watching, or they're taking to social media to discuss it.

The big question is, how good of a job are small businesses doing at adapting to their customer's existing mobile habits?

According to Inc. contributor Jon Miller, not very. Take email marketing for example: nearly half of all marketers aren't designing their email for mobile devices. Miller said that if you're starting to consider how to mold your current marketing strategies to work with mobile, stop there. 

"The more fun challenge facing marketers isn't how to make their existing programs work on a smart phone, but how to build campaigns that wouldn't be possible without mobile," he said.