Very interesting article! But, I wanted to ask you, shouldn’t it be the “optimal level of effort” (not “low” effort)? You reminded me of the notion of ‘flow’: you have to find the correct proportion between skill and task difficulty level to not only attract but eventually sustain people’s interest and engagement. I find this assumption to be even more valid in the digital realm, as in contrast to physical products (such as IKEA furniture). What do you think?