A commercial on television shows a taste test for Pepsi products and Coke products. Every time a taster chooses Pepsi over Coke the word "PEPSI" would be flashed big and bright behind them on the screen. The idea is that even just seeing the name Pepsi at choice times in the commercial is likely to affect the buying choices of people who have seen the commercial. What psychological obstacle to critical thinking do advertisers depend on to affect your thinking in these kinds of commercials, and therefore purchase their products?