As you search for something on certain web portal, it gets registered in big brains of giant media houses (read - Google, Yahoo or Facebook).
Monetization of personal data starts in that instant. Everywhere you go on web and you could see same hotel you searched earlier or same event checked out. So, even if you did not pursue that link in first place, it will appear again and again as you traverse on the web.
Does it really make you buy that particular item or book that particular event ?
Onslaught of advertising have turned us inert to it . Customers simply ignore it as an unwarranted distraction.
So, Brands if you really want to get up close and personal, try to reason with me , influence me and make me look good, entertain me. Spend your advertizing dollars on the blogs I read, products I interact, people I converse with, events I attend.
Just showing that silly pop-up as I check my emails is outright LAZY !!!