The research was based on an online survey of 150 marketers conducted during the last week of March.
It found that the most popular forms of custom content produced by marketers include e-mail newsletters (69%), white papers (50%) and case studies (48%).
Other popular formats include employee newsletters (29%), custom events/road shows (39%) and webcasts/webinars (31%).
Marketers find custom content providers through online searches (30%), asking a colleague or friend (28%) or reading an industry publication (13%).
Also, 15% of marketers produce custom content in house, 11% use an agency and 3% hire a consultant.