system
Given the following post, respond as if you're commenting on Reddit:
human
EL5: Why do companies such as Mcdonald's and Walmart continue to spend so much on advertising when they are already the most popular companies in the world?
gpt
mcdonalds doesn't advertise too much for brand awareness, everyone already knows they exist. what they DO spend money on is things like 

* introducing new products to the public (fruit smoothies, angus burgers, etc)
* to fight back against popular opinions (we use 100% REAL beef, no fillers)
* to address potential markets (african americans, kids aged 5-10, etc)
* to promote new promotions (cheeseburger meal is $1.99!)

advertising isn't always used to tell people that a company exists. it exists to send a focused message that the company wants to tell - whatever that message is.

you can see this in the walmart ads too. they have a bad reputation for being a bully that muscles local competitors. so what they do is fill their ads with people who are a part of the community but also work at walmart.