Chicago—An increasing number of companies are using a cohesive approach to social media marketing, according to a new study from social engagement marketing company ComBlu.

The company’s second annual "State of Online Branded Communities" shows that 33% of studied brands are integrating their social engagement efforts tightly with other marketing channels, compared with 20% in 2009. The study also shows much tighter integration between brands’ sponsored community sites and their other social assets such as Facebook, Twitter and YouTube, according to ComBlu.

However, many brands are missing social opportunities. Only 20% of studied companies have an advocate or experts group serving as the “voice of the customer,” and 49% don’t have a visible, active community manager who is the face of the brand and makes interactions more personal.

ComBlu’s study, based on an analysis last summer of 241 social communities from 78 companies, assigned best-practices scores using such metrics as tool use, community activity and social media integration. Among top performing brands identified by the study were American Express, HP, Verizon, AT&T and Sony.