I really wanted to like Tarsnap and gave it a good hard look for my backup needs. Ultimately my problem was that there's no way for me to gauge how much the service will cost me. Going just by the amount of data in my home dir, it would be cost prohibitive to upload to Tarsnap. The site does assure me that thanks to compression and deduplication, the actual cost will be far less than I might estimate, which is great! But also, as far as I can tell there's no way to have the client give me an estimate of "here's how much data you actually have once the secret sauce is applied". So while the dedup and compression might make the costs far more reasonable, I won't actually know until I pay to store some data. Which means I might find that suddenly I owe Colin a lot of money if the size savings aren't very big due to my data not being very amenable to those measures. That's not a risk I'm willing to take, so ultimately I pursued other options.