Because so many people talk about the subject
Various people start talking about the same event or that controversial subject. Many people would not even agree with it, but still, it become famous as the topic becomes the talk of the town.
New people hear about controversial things through debates
When any controversial topic or event occurs the first thing that happens is debate. Because of this ongoing debate, a lot of people get to know about it. Even people who have not heard about the subject or least interested in it get to know about it through debates.
People are eager to prove themselves right
As the debate begins, people get too much involved in it just to prove themselves right. Because of this ego problem, a lot of fuss creates, which makes the matter even more famous.
There is usually no final word
These kinds of controversial subjects usually do not come to a conclusion, and therefore the debate continues for a more extended period.
The human brain likes novelty
Usually, the controversial matters are unusual ones. It has been observed in various studies that human brains are hardwired to get allured to any new and unconventional stuff.
Some people might try the product to see which party is right
There are a lot of benefits too being in controversy as people themselves try the product that is in controversy to see for themselves which party is right. This increases the sale of the product.
People can go to extremes to prove themselves right
There have been situations when people go to any extent just to prove that their point is right. This might turn the debate into a movement that attempts to prove that whatever they say is absolutely correct not the other one’s opinion.
Negative publicity is still considered publicity
Yes, this is true. Even if someone writes or says anything negative about the product, they would still be introducing the product to many people. If some people try the product after reading the blog and like it, then that person would have done free marketing of the product. (See How to Start a Successful Blog?)
The subject becomes more interesting
If any product or subject comes in controversy, then it becomes even more interesting to talk about it. This leads to a lot of publicity of it and provides more extensive coverage. This can prove either positive or negative for the product.
Controversy can push sales
In a lot of cases, controversy can also help in increasing sales because of the intense publicity that the product gets because of the ongoing debates and discussions about it. (See Methods for increasing client conversion online)