Stephanie points to a nice article about defining the points of engagement. Okay...so, now we have the "what" part of the definition. but, how about the "when"?

We know a two-way communication stream with our customers is vital to long-term success. Hence all the hub bub about connections, interaction and conversation management. But, I still see a tendency to apply the term engagement to the front-end, to the attention getting part of the promotional program. And, that's not really where it belongs. Engagement happens when someone wants to participate, wants to get involved with you and your product because it strikes an emotional chord. And, that almost always happens during or after the actual customer experience...not as a precursor. Engagement is paramount to an ongoing relationship. But, it's not going to work in a thirty-second spot or a cold call. So, for all the ad execs and CMO's responsible for the interruption campaigns, please stop trying to put it the square peg in a round hole. And, please stop trying to convince us that ads are "engaging"...it just doesn't fly anymore.