Why do you use open source CMS products?

There seems to be quite a bit of confusion with regards to the value of the open source CMS market. For this reason, we're asking why you use open source cms products?

What makes you choose them over commercial options?

I've noticed more and more that there are quite a few comments being said that are not factual with regards to the value of open source products. Some commercial vendors, for instance, tend to weigh in with the argument that open source products are not well supported and are less secure than theirs.

What is your take on this? How do you defend the open source CMS market? Or do you agree with these arguments?

We want to know. Comment on this article and share your stories for those who are unsure which way to go. Perhaps you can help them make the right choice, whichever that may be.