In terms of frequency of use, those who have joined the niche social networks seem fairly attached. Among the tech-connected respondent pool, more than 80% of users of each site logged in at least once a week. More than three-quarters of Twitter users logged in every day, as did those on Facebook.
Photo-focused sites, particularly suited to mobile, seem to be especially popular. Instagram saw 70% of users logging in daily, and the relatively new Snapchat was just behind with 67% of its users logging in daily. Read the rest at eMarketer.