E-mail when integrated with which of the following marketing tactics delivers the best ROI?

One of the greatest benefits of the rise of the internet was the ability to use email to communicate with people. Then email was used as marketing purpose due to a number of reasons:

•    Reduced time & effort , it’s real-time
•    Emails can be personalized , and it allows business to segment users, and track sales and user engagement
•    Email allow us more frequent communications  and more easily to spread the message

Later, due to the above advantages, email was integrated with some approaches for marketing purpose. The research shows (see the graph below) that businesses will gain better ROI when integrating email marketing with online marketing and social networking site. Their ROIs are above 50% and 40% respectively. Integrating email with Radio received less than 5% of ROI. This chart also gives an insight into what are popular with users such as people spend more time online and on social networking than listening to radio channels.

If you are a marketing professional or have a business, do you have similar experience? Or would you like to adjust your investment and get better value for money.

Graphic data source: statista.com