Doylestown, Pa.—Two-thirds of companies view social media marketing as important or very important, and 70% spend at least one hour a week on social media activities, according to a study by agency Sagefrog Marketing Group. According to Sagefrog's "2012 B2B Marketing Mix Survey," involvement in social networks are the most favored social activity of companies, cited by 79% of marketers. The favorite social network is LinkedIn (79%), followed by Facebook (65%), Twitter (54%), YouTube (40%), Google+ (30%) and Pinterest (9%). Following social networks, blogging (48%) is marketers' second favorite social activity, with microblogging, video sharing and forums/communities following in order. Sagefrog's online survey was conducted in June, with 160 respondents.