Dive summary:

• There are a limited number of ways online that advertising can lead to engagement from the consumer.
• Due to this clutter and fragmentation, the most valuable commodity for advertisers that want to build brand value -- in any medium -- is engagement.
• The main methods of getting consumer interaction online are email marketing, search, social, rich media, and retargeting, and the best method is a combination of the approaches.

From the article:

High engagement rates demonstrate the value of consumer attention, and also prove the level to which you can take the creativity of your message when you work with a flexible, scalable platform and network. ...