Researches are not always right you know, experience learns you which research is good and which is not...
Email marketing it's done right, believe it or not, but because lots of people are afraid of phishing and are not very up-to-date with the news they consider it's better to mark as spam a new marketing email rather than "clicking on a link that could steal their money from their accounts"
Each guy consider something else I do not deny that, but from my experience in sales I KNOW for sure that telemarketing works, maybe not like online marketing (for UK for example) but it works and brings new clients to your product.