Read the May 2012 commissioned study conducted by Forrester consulting on behalf of Sitecore, "The Multichannel Maturity Mandate: A Research Study Finds Proven Results, Significant Faults, And A Path To Higher Gains."
"In late 2011, Sitecore commissioned Forrester Consulting to research current and planned practices in multichannel marketing. We found that marketers who have adopted multichannel marketing practices have realized significant business benefits, ranging from improved campaign performance to higher return on marketing investment (ROMI). Evidence suggests there is opportunity for additional, significant gains through better organizational alignment, process definition, and technology integration." - Forrester Consulting