A positive user experience so far for me. I've clicked on a number of adverts for widgets I had recently shown an interest in through my search history. Targeted adverts down the make and model. Good for me, and got me clicking on adverts when I wouldn't have usually. And their appearance also re-ignited my interest in said widget even though my mind was on other matters when the advert appeared (i.e. the sites had totally unrelated content but it made me go back to looking at buying the widget in question).