After the movie, my boyfriend Blaine commented that he thought the original Lorax movie was much better than what we had just watched. Prior to that, it never even occurred to me that there'd be an original, so I had to check it out for myself. And after watching Dr. Seuss' The Lorax (1972), I have to admit... Blaine is so right.
So to list a few examples:
The thneed is a smart product because it aims to satisfy the consumer's economic needs - it is versatile and useful. As the Once-ler attempts to market to the Lorax: "This thing is most useful / This thing is a thneed / A fine something / That ALL people need"
At 5:36, the Once-ler puts up a sign that says "LAST CHANCE TO BUY THNEEDS FOR 100 MILES", and displays a thneed right next to it. I thought to myself ha, that's not going to work. However, the sign proved to be an extremely effective cue. A random car that drove by and saw the sign turned back around and purchased the thneed, despite not knowing what it was or does and regardless of price.
At this point, it was obvious that the Lorax did not agree with the Once-ler's doings. But the Once-ler had already put his personal needs first and omitted his social needs.
He has also completely abandoned his social responsibility. While the Once-ler was successfully establishing his business and making tons of money, things were happening for other residents too. Their environment was getting polluted, their truffula trees were disappearing day by day etc. But with his selective exposure, the Once-ler has only been taking in the good.