DISQUS

Daemonic Dispatches: Tarsnap and the prepaid billing model

  • ryan · 8 months ago
    One other place you can look is amazon fps, or paypal micropayments. They are there if you look, . 5% and .05 cents typically at the worst rates. so for your lower end users this would still be somewhat profitable. https://www.paypal.com/IntegrationCenter/ic_mic...
  • cperciva · 8 months ago
    Unfortunately, Amazon FPS is not available in Canada (where I am) -- otherwise I'd definitely sign up for that. Paypal micropayments might be an option, but it sounds like I would need to have two paypal accounts to do that (one for for standard fee rate and one for the micropayment rate?) -- so I'm not sure if it makes sense to do this; but I'll certainly look into it.

    Thanks!
  • ryan · 8 months ago
    I am sure Amazon will expand to Canada soon. They just started it, maybe contact them and ask them to be a beta tester for Canada. Also, for the paypal micropayment system, yes you will need two accounts. Just do like they say if the charge is over $12 then use the 2.9% .30 account to charge it, if less than $12 use the microtransaction account. I believe you have to do the same for FPS and DevPay on Amazon. Currently only using DevPay but looking into FPS. Good luck, finding profitable means is usually a little bit of science, hardly ever works with your first shot or with one type of stream.
  • cperciva · 8 months ago
    I've made several people at Amazon very much aware that I'm looking forward to FPS being available in Canada. :-)
  • ssp · 8 months ago
    Ever since I heard of tarsnap I have wondered what would happen if you multiplied your prices by 100 (or more) and tried selling it aggressively to enterprise customers.
  • cperciva · 8 months ago
    I'd probably make a lot more money. :-)

    On the downside, I doubt I would have any of my current customers; and the few people using tarsnap wouldn't be anywhere near as enthusiastic about telling their friends about it. As a result, I'd have to spend a lot of time and money on marketing. I don't like marketing -- I'm not good at it, and moreover it would take my time away from working on making tarsnap better.
  • Mark MacLeod · 8 months ago
    Colin, thanks for sharing my post. I am amazed that you make money with this average revenue per user. And you're absolutely correct about the cost of payment processing. Sounds like your approach is a good one.
  • Jason DiCioccio · 8 months ago
    Keep up the great work! I use and love the service..
  • Robert · 8 months ago
    Been awhile since I've checked in on the tarsnap project. I gotta say I like the concept of service layering to Amazon S3.
    My only question, Colin, is what is the mitigated response to such an instance where Amazon cancels the particular service
    in use. Or as in another situational case, Amazon corrupts data in this service rendering the backup unusable.

    Firstly, I feel that both cases are quite speculative and not foreseeable. But when talking about backing up its always good to have
    a backup plan for the backup plan!

    So for the first instance (Amazon discontinues service). Would you see it quite conveniently possible to move the service to a set
    of private servers or another commercial host without service loss (at least minimally).

    The second situation seems even more unlikely. My questions here involve underlying storage practices (do they snapshot their systems
    in the case of failures) and the guarantees of backup resiliency under stress. To clarify, what and who ensures that backups are being
    protected against fault. I find it incredibly odd that some backup companies often disclaim that you should ensure you have your own
    backups so that they aren't at fault if something happens. My only response to that is while it is always correct to have as many backups
    in different locations (securely) as your data or paranoia requires, but that the backup service provider's sole purpose of existence is to guarantee
    the CIA (confidentiality, integrity, and availability). I guess I'm more or less interested in the interpretation of liability for this kind of service
    and not that this situation is very likely.

    Thank Colin for your contributed work to FreeBSD and projects like this!
  • cperciva · 8 months ago
    If Amazon suddenly decides to kill S3, I could migrate to a different host. There would be an outage while the migration took place, and any new host would likely be far less redundant than S3 is right now (one of the main reasons I'm using S3 is that I trust it more than anything I can build in the short term), but the tarsnap service would not die.

    If Amazon silently corrupts data on S3, well, there's not much I can do about that. Corruption won't go unnoticed, but it's impossible to guarantee uncorrupted backups if you can't rely on the underlying storage to some extent -- I could replicate everything offsite, but (even leaving the issues of cost out of the picture) if I did that you'd just be asking what I'd do if S3 and my offsite storage simultaneously corrupted data. Everything I've seen of S3 indicates to me that Amazon is quite conservative about making sure that data will not be corrupted, so this isn't a scenario which I'm particularly concerned about.
  • Jimbob · 7 months ago
    I love that you consider "the logarithms of [something] follow a normal (aka. Gaussian, aka. "bell curve") distribution" to be for "the non-statisticians" :)
  • sriramk · 5 months ago
    One option I would like to see is to have an automatic addition to funds. When my balance becomes $0, you could increment it by $10 automatically (provided I had authorized you to do so earlier). I just put $10 into my tarsnap account and I'm wondering whether I would need to remember to keep my account funded every few months
  • cperciva · 5 months ago
    Don't worry, you'll get an email warning you when your account gets low, and another email warning you if your account balance falls below zero (at which point you'll have a week to add more money before your account expires).

    Automatically charging a credit card as needed is something a few people have asked for, so it's certainly something I'm thinking of supporting in the future -- but the costs associated with that are quite high (e.g., I would need to store credit card data) and the prepaid log-in-and-deposit-money-when-you-get-an-email system seems to be working quite well, so this isn't a high priority.