[jondubois]

But maybe if you didn't see that ad, you would have come across a different product/service which is actually better quality. Maybe your expectations of quality have slowly eroded over time (because of advertising).

For example, in the old days, most items of clothing would last a lifetime. These days most items of clothing tend to fall apart after a few years. Also, many kinds of food items used to be better quality (I've read many articles about how low the quality of farmed vegetables like Tomatoes have become).

I think that even Mcdonalds' used to be much better quality 20 years ago. At first I thought it was just because my memory was fuzzy but I later found out from someone who worked at McDonalds that one day, they suddenly swapped the buns of the Quarter Pounder burger to smaller buns but no one noticed except the employees.

Also big Pizza chains in some countries have been making the pizzas smaller and smaller over time in order to maintain the low prices. Advertising allows big companies to keep pulling back on real quality whilst replacing it with an illusion of quality.