Selling data online -- how??

November 15, 2007 4:45 PM

I have about 200 binary data files totalling about 60 GB that I want to sell online. How should I go about doing this?

I suppose this is no different from selling a shareware program, except that I would have 200 files to sell.

I checked out Regsoft but their site is confusing... if you click on Sign Up Products and it goes to a redirect page that goes back to the original site. WTF? I am wary about dealing with them, and it looks like they are tied with Digital River which I recall several years ago did aggressive, HARD selling... cold calls, spam, the works.

I also considered just hooking up a drive to my computer and running a server here on my home DSL account. I expect very little volume so it wouldn't be a big deal. However I have no way of instantly processing transactions (though I could probably receive orders on my Paypal account). Even so, I have no idea what sort of software I should be running or if I need to code something from scratch.

Can someone point me in the right direction?

posted by chef_boyardee to computers & internet (8 comments total)

This seems like what ftp was made for, it should be a cinch if you're unix-y at all. I'm sure you could get GUI clients to do the same thing. Get an FTP server running on your computer.

1) advertise
2) Purchaser drops a cheque into your paypal
3) make an ftp login for the purchaser (make sure they only have access to the files they've paid for, obviously) and email them their username/password and the ip of the server.
posted by tylermoody at 4:55 PM on November 15, 2007

Is there a reason something like PayLoadz would not work for you?
posted by needled at 4:58 PM on November 15, 2007

Just to clarify (because I think it makes a difference) are you selling them ala carte or as a single package of 200 files? Also are you looking to sell enough copies to warrant an automated payment/processing system, or is it something you could do manually for each transaction via paypal? Clearly there are a lot of building web stores, some of them for digitally distributed products, but that may be overkill for what you are doing.
posted by frieze at 5:07 PM on November 15, 2007

Protecting files from download over http can be messy because the mechanisms aren't very fine-grained.

If I were you, I would encrypt each file with a different key (have a look at gnupg for this purpose though I'm sure there are other easier tools with GUIs to use, perhaps gpg4win for which there is a link on that page) and put the encrypted versions up on an unprotected http or ftp download directory. You could even give them out via bittorrent if you expect there to be multiple concurrent downloaders or your connection to be flaky - no one wants to restart a 300MB download because of a few dropped packets.

When someone purchases a file from you, you email them the private key required to decrypt that file. Make sure you give very detailed instructions on how to use the crypto you've chosen.
posted by polyglot at 5:34 PM on November 15, 2007

tylermoody: I am trying to do this all automated... I have no problem operating a server at home but there's no mechanism I can think of for protecting non-purchased files.

needled: PayLoadz looks like 1996 Internet pricing... they want $260 a month just to store 1 GB. I can understand imposing premiums on bandwidth, but storage is ridiculously cheap these days.

frieze: I'm offering single ZIP files for purchase... most likely someone will only want to buy 5 or 10 of them at most.
posted by chef_boyardee at 5:56 PM on November 15, 2007

If you're good with scripting, you can get notifications from PayPal of a payment that include the buyer's email address. Snarf that with procmail or something and feed it to your script that:
- looks for which items (files) they ordered
- checks the transaction value
- emails the buyer the appropriate URLs and keys.
Since you mention the possibility of running a web server on your DSL, I presume you can run stuff like perl or PHP to do the tricky parts.

If you're a verified member of PayPal they will accept payment on your behalf in very simple ways, i.e. you put a link on a page containing the relevant purchase details, just like those PayPal donation buttons you see everywhere. You get an email for each payment.
posted by polyglot at 6:20 PM on November 15, 2007

Who's your target market? Are they technologically literate? Geeks? What platform will they be using? Are they going to be highly motivated purchasers (people who are going to want what you're selling enough to go install some software they might not have already) or are they casual consumers?

All that influences what sort of retail channel you can use. If you were selling to a fairly geeky crowd, or to motivated purchasers who aren't going to be opposed to jumping through a few hoops, I'd do as polyglot suggests. Encrypt each file with a different key using PGP (using the symmetric key option), then toss them all up on an anonymous FTP server and don't worry about access. Anyone can download anything they want, but without the key, they won't be able to do anything with it (for a few dozen years, anyway).

GPG is the best way to do this, but if you want to be a little more mainstream, or if your target market is less geeks than warez/script kiddies, you could use encrypted RAR files. They're not hard for someone to figure out how to undo, and I think they're fairly secure.

Password protected Zip files should not be used, as I believe they are pretty trivially breakable.

Alternately, if encryption is for some reason not an option, you could do FTP with limited user accounts, but that's going to require a non-trivial amount of setup for each customer, each time they order.
posted by Kadin2048 at 6:28 PM on November 15, 2007

Use paypal- once the purchase is complete, have a script run that will copy the purchased files to a folder (based on transaction ID) and send the customer that link.

For protection, please don't encrypt/password protect your files. If your volume is low, I doubt you will have to work about privacy.

The easiest and non intrusive would be to tag your data files on the fly with the customer's name (are they PDFs?), if you can't, at least name them with the customers name somewhere in the filename.
posted by mphuie at 9:21 AM on November 16, 2007