I'm paying for Gobbler ($40 USD per year), but I can't really use it as a back up tool except for my current project. My projects are too big and I can't afford the amount of storage it would require to backup the last 15 years of noodling. My subscription level allows me to send unlimited about of links to friends with projects or wave files.
Over the last year, they've incrementally increased my storage quota as my various musician friends have created accounts.
Things I use it for...1. Sharing a project with a friend
2. Keeping my current project backed up so I can do incremental restores if necessary (pretty much the same as using save-as periodically, but if your hard drive fails your still covered).
3. And this is the biggie - Sending Huge numbers of Wave files to specific people who have to create an account to download and cannot forward the link to all their friends!
4. Creating general links that work for a week that anyone can use to download the content (so you can post it to Facebook et al.).
Things I had to get good at1. Putting it on pause so it doesn't burn my wire/processor all the time. My projects are often 3+ hours long and they can't analyze all my waves to see if they need to be uploaded every time I hit save.
2. Deleting projects out of Gobbler so I could upload more stuff.
Generally, I haven't seriously considered cancelling.
It's saving me time burning CDs and delivering them which justifies the $40 USD by itself.