I think this is an interesting train of thought, although I doubt effort will ever go down to zero. After all, we derive pleasure out of many things we do which take effort. I'll often travel to meet a friend for dinner, even though I could've eaten at home, and talked to her over voip and webcam.

I think more so, we're minimizing effort per quality of interaction - or maximizing quality of interaction per effort.

Lower effort per interaction is only a net win if the value of interactions remains constant and the number of interactions doesn't scale up to compensate for the decreased effort.

In short, my experience has been that as communication in general has gotten easier, the average individual communication has gotten more trivial, and the signal/noise ratio has worsened.

I'm not at all convinced it's a net win.

Product people are always preaching this. Every interaction should be judged based on the return of that investment (the investment being the interaction). If the product improves and can deliver that much better of an experience (matching and exceeding user expectations), then that interaction is worth it. Each interaction should be prioritized according to this ROI and then chosen based on achieving product-market fit (PMF).

Also, this appears to suffer from what I like to call the "Razor-blade Singularity" fallacy: http://www.economist.com/node/5624861?story_id=5624861

Effort per interaction will only be zero when interactions require no cognitive overhead. In which case, why are we bothering with them?