

Interesting statistics from the tarsnap backup service - cperciva
http://www.daemonology.net/blog/2009-08-21-interesting-tarsnap-statistics.html

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jacquesm
Unearned revenue is a very interesting bit of data, I'm all for transparency
and all that but you may actually be giving people ideas here. It's a great
source of income because essentially you can play 'bank' without any of the
penalties, if you can park 6 months of turnover in an interest bearing account
you could add 2 to 3% or so to your bottom line.

As for other interesting statistics, one of the more important one is life
cycle, how long on average does an account live. If you multiply your number
of signups in a given month with the lifecycle you can figure out an upper
limit to how far your business will grow organically (without additional
promotional activities).

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cperciva
_It's a great source of income..._

Have you seen the interest rates banks are paying these days? Interest on
unearned revenue is non-zero, but not by far.

 _As for other interesting statistics, one of the more important one is life
cycle, how long on average does an account live._

I can't give you any accurate statistics on that, for two reasons: First, the
number of tarsnap accounts which have ever closed is too small to be
statistically significant; and second, because tarsnap doesn't have any fixed
monthly fees, people can leave their accounts inactive forever and never have
them die.

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jacquesm
They're pretty good this side of the pond, currently about 4 to 4.5% on a one
year deposit. Maybe you could find a way to take advantage of that.

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byrneseyeview
Sadly, he'd either have to take on currency risk (if his assets are in Euros
and his liabilities are in Loonies, and the Euro drops relative to the Loonie,
he's lost money that wasn't his). Or he'll have to hedge -- but there probably
isn't an arbitrage opportunity there.

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cperciva
Tarsnap's unearned revenue is in USD, not CAD -- but aside from that, you're
exactly right. I can't earn more interest without accepting currency exchange
risk.

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sachinag
And he can't put it into CDs because of liquidity risk.

PayPal's first business plan was to make money on the float. That didn't work,
so they started charging (ever higher) fees. In the history of the world, I
don't think anyone's ever made their money on the float.

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ensignavenger
Warren Buffett

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cperciva
Yes, but I'm not Warren Buffet. :-)

A more useful comparison would be to Jeff Bezos: Even disregarding unearned
income, tarsnap produces roughly 1.5 months of float due to AWS billing a
credit card at the end of each month (0.5 months after usage, on average)
which has a billing period ending 3 weeks later (0.75 months) and which has a
long enough grace period that I can wait another week (0.25 months) before
paying off the credit card bill.

This "negative working capital" model is one of the reasons Amazon could grow
so quickly in the early years -- and makes it very unlikely that I will ever
need to raise capital to fund tarsnap's growth.

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thinkzig
I'm not sure if you'd be willing to divulge this information, but just out of
pure curiosity I'd be interested in knowing what types of files people are
backing up. For instance, across the whole service, what are the top 10 file
types that are backed up?

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cperciva
_what are the top 10 file types that are backed up?_

I have no clue. If I could figure out what data people were storing, tarsnap
wouldn't be a _secure_ backup service, would it?

(For that matter, I don't even know how many files people have archived, or
how large they were prior to being compressed.)

