I'm not making any money off of hubpages. I may do so in the future, but right now it's not my primary interest.
I joined because there were forums for writers and I like to be able to ask questions and opinions about the things I'm writing.
After joining, I wrote a couple of hubs and found I enjoyed it. I answer questions every now and then and ask a few. I've written some hubs and plan on doing 1 or 2 a week from now on.
I'm just about to publish my book as an ebook and thought this would be a good way to promote it and maybe sell a few extra copies too.
Other than that, trying to earn a few dollars from ads when I'm only writing a new hub every now and then seems like more work than I'm willing to put in at the moment. All of my focus is on writing my books. :)