Being able to respond online to printed marketing was the most important way to make people react and purchase a product, with people 20% more likely to comply.
CDMS's survey of 2,000 UK consumers also showed that personalised DM rated highly, with respondents 14% more likely than average to respond and purchase.
The company said DM was more effective when it used variable data to target individuals, combined with personalised URLs.
Consumers were 17% more likely than average to respond if the campaign was time-sensitive or triggered by a particular event.
Although online options generated the best responses, CDMS said print should still be used as the primary communication method.
Head of marketing Richard Higginbotham said: "Mail is appealing and a personal medium while the internet is generally used by consumers to check and compare."
He claimed that by solely pushing a promotion online, companies are inviting customers to make comparisons with other products and services.
"Use print to engage the client and the internet for gaining responses," he added.
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