Interactivity: you're doing it right

Exhibit 1: TED-Ed 'flip the lesson' tool for learners/ teachers. Here's why I feel they're doing it right: they address the matter of creating and customizing the context to a material (rather than relying on a Gimmick of the Day that should in theory "keep the learner engaged"). Here's what they have to say about it:

Why is contextualizing a lesson important? Because every learners' needs are different. /.../ When you "flip" a video you get to decide which of those materials you keep, and whether to craft your own. This will allow you to relate the resulting lesson to your class, to an individual learner, or to a wider group.

Plus, the animations are pretty cool by themselves too.

Exhibit 2: Crash Course World History series. Here's why i feel they're doing it right: never during these series have I felt that they're trying to prompt me, the learner, to artificially click somewhere or perform a specific action in order to "stay on channel". Yet, all the way through the series, I can feel they are making me, the learner, actively think along - and succeeding in it. Here's one of their interactivity weapons: The Mongols (who else)!