Tony Edgecombe

Like most software developers most of the traffic I get from download sites comes from CNet and Tucows. The other three hundred or so sites generate a fraction of the downloads that these two create.

There is a cost to listing on these sites, a small fee to get listed quickly or at all but more importantly the time managing updates or fixes for stolen key codes. My problem is I don’t know whether this investment in time and money gives me a large enough return, one of the most important things I figured out about this business is not to invest if you can’t measure the return you are getting.

Normally I track customers at my site by setting a cookie when they first arrive so by the time they get to order the software I can see where they first came from. For both CNet and Tucows this isn’t feasible as they host the software on their servers so the customer will download and try without visiting my sites.

The way I am doing this is by embedding the id of the download site in the file name of the program, for instance setup.exe is named setup_cnet.exe for the CNet site and setup_tucows.exe for the Tucows site. The installer stores the setup name in the registry and a small linking tool reads that information and embeds it in the url when launching the web browser, when the customer lands at my sites a cookie is set and tracking is working again.

Serving up a different file for all the download sites and affiliates would be a nightmare but fortunately Apache the server software on my web host supports a facility called url rewriting. This allows you to serve a different file to the one requested in the url, in my case CNet links to setup_cnet.exe and Tucows to setup_tucows.exe but the actual file downloaded is setup.exe. The important thing is this isn’t a redirect so the filename remains intact when downloaded. Enabling this required just two lines in my .htaccess file:

RewriteEngine on
RewriteRule ^setup_[a-zA-Z0-9]*\.exe$ /dl/setup.exe

This works by matching the url with a regular expression, anything starting with setup_ and ending with .exe and serving up the setup.exe file instead.

Storing that information in the registry is fairly easy, I use Inno Setup to create my installers and that has a variable {srcexe} which holds the path and name of the setup program. I just store that whole path in the registry ready to be read and interpreted when the user selects a link in the software to my web site.