It is obvious that a growing number of things and environments are becoming increasingly interactive. This means that we as humans in these environments have to interact with these things in a more sophisticated and deliberate way. At the same time we know that any interaction, or interactive session, requires some time, effort, and attention. This means that there is a cost of interaction. A really simple exmaple of this is when I am looking for something on the web, and I find a page but in order to get the stuff I am looking for I have to interact and to create an account etc. Of course, the purpose is that with an account I can get more and better service, but it comes with a cost of interaction, and in many situations I judge to cost to be too high and leave the page (even though the "cost" was only to write my email and straightforward info).
Is the overall interaction cost increasing since our things and environments are increasingly becoming and requiring interaction? Is there a limit to how much we want to "pay". When and why do we chose non-interactive alternatives? When do we look for interaction and when do we find interaction unacceptable?
Well, it is possible to ask many interesting questions around the notion of the cost of interaction, and I predict that this will soon become a very important aspect for all forms of interaction design!