Direct mail is not invasive in the same way that tele-sales is invasive.   I can collect the direct mail and drop it in the recycling bin outside my house or at my office, and really nothing much has happened to invade my life.  I do the same with my daily paper once I have read it.

But telephone calls interrupt me, stop my flow of work, cut across my life when I am watching football on TV.   Now that is invasion.