Here are some "reasons for existence" I have noticed. I challenge you to come up with more! -Val
If the quality of the content attracts a lot of people, it makes the website more attractive to advertisers.
Sometimes the "store" is entirely online.
Sometimes it isn't a "thing" that is being "sold", but an idea.
Journals are judged to be either legitimate or vanity press, depending on the rigor of their peer-review process.
Some publishers prey upon people who want to be published by publishing anything for a fee.
When something is published for a fee, regardless of quality.
Students make websites and blogs as part of their education.
Web-based socialization is making it possible for people who do not fit into their IRL (In Real Life) situation to find a support group of people to socialize with.
Some people like to generate drama.
Letting people know of safety issues, or publishing information for the common good, improves the society you live in.
The government wants healthy people that work, earn money, and pay taxes to support the govenment.
The backbone of the internet is Commerce. When you see the .com you know it is a commercial enterprise. Some of the other domains are harder to judge. If you have questions about domains, please feel free to contact me at firstname.lastname@example.org.