eMarketer reports that according to a market study performed by Network Solutions and the University of Maryland, small-business social media marketing use has apparently plateaued in the U.S. at 24 percent adoption.

The study of American small to medium businesses (SMB) found that most primarily use Facebook (82 percent), and that common activities are maintaining a "company page" on a social network and posting status updates or links to interesting content.

About half of those businesses that used social media also monitored social networks for mentions of their company and/or product names.

As small business gains experience with social media, some have realized their expectations are not in tune with reality. As most begin to look at social media as a channel more for customer loyalty than for prospect acquisition, they're also finding that hopes for increased brand awareness and attracting new customers have not been fully met.

However, while fewer small businesses expected to use social media as an engagement channel, nearly two-thirds have actually had success in that area. Customers are "connecting" with companies through sites like Facebook and LinkedIn, but relatively few sales leads are captured.

Small businesses have found other frustrations. Many say their online activity requires more time than they had expected, although those concerns dropped from 50 to 43 percent between December 2009 and June 2010 -- perhaps suggesting SMBs are being more realistic about their social media marketing campaigns.

Also, those saying their business had been criticized online nearly doubled, reaching 29 percent. Regardless, just 1 percent of small businesses said their image was hurt more than it was helped by social media marketing activity -- down from 6 percent.