A little bit of fertilizer is ok.

Doing some sales promotions is ok.

Too much fertilizer and you'll fry your lawn.

Too many promotions, and you'll fry your brand.

Les Binet's comments on price promotions

https://www.marketingweek.com/les-binet-price-promotions-recession/

Consumer behavior information from Michelle Klotz

https://insidebe.com/articles/the-dangers-of-discounting/