The reactions in here seem a little split.
I want to approach an important issue though, the idea that people "choose" to spend money and so we have no moral responsibility to them.
Retail Psychologists have literally spent decades ensuring that you are manipulated subconsciously to make buying decisions. The tempo of music in your supermarket, the scent they deploy through HVAC defusers at clothing stores, the layout of furniture stores, the color of the walls. All of these things are organized to affect your subconscious to ensure that you spend a higher percentage of money per year at that store, to transform window shoppers into repeat customers.
As a society, we are responsible for that. We allow these practices to continue even though they actively manipulate the consumer in a way that doesn't allow for informed choice.
The person who spends two hundred dollars on Hearthstone cards because the color and sound of the pack opening is explicitly designed to activate and engage pleasure in the subconscious is also being manipulated. If we agree that this is alright, then we are accepting that companies have the right to use signals that we're not even aware of to try and sell us more things.
I, for one, don't believe that it is acceptable for companies to use subliminal messaging to influence my decisions as a consumer. Even though our choices are affected by many subconscious signals from all areas of life, I still don't want Walmart to use those tools to make me buy more Oreos, and I think I have a moral obligation to make sure that Walmart isn't making other citizen who might not want to buy all those Oreos make bad decisions.
Part of living in a society is deciding to what extent we believe we are responsible for the well being of others, and multi-million dollar companies using psychology to encourage people to spend money in ways in which they cannot make an informed decision falls into my "I care" camp.