In this one:

http://www.oreillynet.com/onlamp/blog/2004/08/say_no_by_default.html
Say no by default - in design, business, and even life.

Simple is beautiful.

Instead of doing something "because you can", consider thinking "only if necessary".

   In other words, if one is an English learner he almost "automatically" going to be my friend (by default). Won´t be, if he don´t want (for any plausible reason), that´s why I put the 'almost' there. 

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   Ah, the guy in the above feature, meant you must change the positive signal (by default you buy something, only because you can afford (or have credit), for the 'NO'.

    In doing so, the 'burden of buying' is turned into the 'burden of selling'.

      Clarified? 

      Hugs, see you again, PP.