I selected to sync everything, but when I view my quota, my add-ons are always using zero memory. Everything else is non-zero. I'm using only a few add-ons, but they are very important to me, and I want to sync them to my other computers. I did see a similar question earlier which suggested to wait an hour. I have waited overnight. Interestingly, right now my server quota shows that my tabs aren't using any space either. This is a step backwardes, as last night tabs were occupying space.