Glad you're happy with it. I went with BorgBackup which I'm also happy with. AFAIK it also does dedupe, encrypt, checkpointing, and can throttle upload speed (don't know about the rest).
One of the things I value about Tarsnap is that I can set a permission which does not allow data to be deleted. That is, if a hacker somehow gains access to my server, she cannot delete all the existing backups.
More generally, I suspect you are underestimating the number of people who tick one or more of these boxes: (a) Impressed by Colin's security chops and the security focus of Tarsnap such as its Bug Bounty program; (b) Have never heard of BorgBackup; (c) Value customer support; (d) Are worried that an open-source project would not be maintained and prefer a vendor whose livelihood depends on the product (d) Have experience with Tarsnap on previous projects; (e) Only need to store 20 Gb and for whom saving $5 per month is unimportant; (f) Have revenue in the millions and for whom $75 per month is a rounding error.
Even if there were no such people and Tarsnap's new user growth was zero, it might still make sense for Colin to triple the price of Tarsnap in order to maximise the income from existing users.
> ... I can set a permission which does not allow data to be deleted. That is, if a hacker somehow gains access to my server, she cannot delete all the existing backups.
With GCP/AWS, you can copy and paste a bucket ACL that only allows PUT operations, and enable versioning to ensure nothing can ever be deleted by overwrites.
With tarsnap there is one person who can delete all your existing backups - Colin, because he owns the bucket. And he will for sure within 7 days of your account falling below a $0 balance.[1]
That might be a feature in case you got killed in a car accident and you want some secret to be buried forever. But for me, I'm archiving my family photos/videos and I'd rather AWS keep charging my account and keep my data alive until my estate can sort out my digital data, which could take months.
> it might still make sense for Colin to triple the price of Tarsnap in order to maximise the income from existing users
And there's the rub. I don't like the idea of somebody holding my data hostage. I'll gladly contribute to a Patreon if an open source developer needs recurring support.
Those are good reasons to choose BorgBackup over Tarsnap, but they aren't related to your original claim about pricing. There are two questions here:
1. What are the benefits and market size of Tarsnap compared to other backup solutions like BorgBackup + GCP?
2. Would Tarsnap make more profit it it raised its prices?
We seem to be arguing about question 1, but Patrick's advice to Colin is about question 2. Earlier you pointed out that Tarsnap is 25 times more expensive than GCP which indicates that Tarsnap's target market is not very price-sensitive. If Tarsnap doubled its prices for new customers would the rate of new signups really drop by more than 50%?
To be fair, GCP/AWS also don't have unlimited grace periods if you fail to pay. At some point everyone deletes. That's why you should always have two backups with different providers using different credit cards. A blocked credit card has led to failed businesses in the past.
Right, didn't mean to imply they didn't. But the differences are that Tarsnap is pre-pay[1], while AWS/GCP automatically debit your card.
How many people have several months, or a year, of runway on their Tarsnap account balance? Meanwhile, there have been cases of people being dead for years[2] with their auto-pay agreements keeping everything humming along while they rot. Keep in mind that recurring payment agreements often aren't cancelled when a credit card number or expiration date changes.[3]
Finally, AWS will give you about five months of unpaid bills before they suspend your account and delete your data.[4] I would assume GCP has a similar policy.
More generally, I suspect you are underestimating the number of people who tick one or more of these boxes: (a) Impressed by Colin's security chops and the security focus of Tarsnap such as its Bug Bounty program; (b) Have never heard of BorgBackup; (c) Value customer support; (d) Are worried that an open-source project would not be maintained and prefer a vendor whose livelihood depends on the product (d) Have experience with Tarsnap on previous projects; (e) Only need to store 20 Gb and for whom saving $5 per month is unimportant; (f) Have revenue in the millions and for whom $75 per month is a rounding error.
Even if there were no such people and Tarsnap's new user growth was zero, it might still make sense for Colin to triple the price of Tarsnap in order to maximise the income from existing users.