What Brick and Mortar is Up Against - an Example

I recently tried on a dress at a clothing store across the street from Joie de Vivre.  I loved the it, and wanted it, but they did not have it in my size.  I asked them to see if they could order me one, but they called me later to say they would be unable to get it until January - too late for my dress need!  I knew the name of the company as I had also bought one of its shirts, so when I was sitting home one afternoon, I googled it to see if I could find the dress.  I did, within seconds. Didn't order it though, wasn't sure what size I did need, if I really needed it, etc, and clicked out of their site and onto another -  - maybe the New York Times, maybe Facebook.  The instant the new site appeared - the instant - up popped an ad - for that very clothing company.  I had never seen one of their ads before.  And in the days since - that clothing company pops up almost everytime I am on a site that has any ads at all.  It's relentless.  But it really helps me understand why people order things off the web.  They might prefer to return to a brick and mortar store - in a perfect world - but maybe it's raining, or maybe their kid is sick, or maybe it's the holidays and they're just crazy crazy busy . . . and there it is - the item that they want, popping up everyplace.  What could be easier than just placing that order?  That is one of the reasons the customer who says they'll be back for something never comes.  And doesn't think - oh, Joie de Vivre could probably ship me that item.  Of course, maybe they just changed their mind; I'm not completely paranoid.  But seeing the web work its insidious magic was both fascinating and sobering!