Sometimes you knowingly create a user that has internet facing content, and sometimes it just comes by default. Here are sites were you can find things written by me.
MyAnimeList, also known as MAL, allows anime fans keep a record of what anime/manga they have seen, or you plan to see, etc. It's great to share with other similar fans to quickly connect. There are also cool apps that interface with this website.
Google Plus has turned out great for communities - I use it for that almost exclusively. You can see all my posts with that link
Yup, amazon has public profiles by default. You can see my reviews for things I have reviewed (favorably only). Amazon didn't publish the one where I complained the cat food I was ordering always arrived all banged up, to the point some would crack open in transit and I was regularly throwing a couple straight to trash. That's another good thing about having your own webpage, you get to tell the world things that Amazon would like to hush >)