Actually, this makes a lot of sense. The more often you visit the page to check the status of sales, the more likely you will make impulse purchases. That is why companies pay the advertising agences, based on the number of clicks on the site link. It really isn't a question of "needing to do it", it's a business decision after all.
The cost of the ingredients in a 30 ml bottle is between 75 cents and $ 1.50 depending on ingredients used. Most of the rest of the cost (rent, utilities, employee salaries, etc ...) are fixed. Smaller profit margins and larger volume, makes sense for some businesses. That is why a company like DeKaang or Hangsen can afford to sell their juice at "only" 200 or 300 % markup on the cost of ingredients, compared to the customary 400 to 2000 % markup of some U.S. vendors, and still be more profitable than their U.S. counterparts.
Sorry, off topic, you might have made an off-handed explanation for the sales policy, but it makes complete sense !