When installing Google Chrome, the web page asks your whether you want to set up Google Chrome as a default browser:

This being a form submitted to the server, how does the result of this checkbox make it into the final installation on the client, if at all?
Does the checkbox only tell the server to send a different installer? Or is this possibly just a social experiment where the checkbox has no effect, but the results are being aggregated and analysed?
For Chrome specifically, I just tried downloading both installers (with and without the “default” option) and found that they do indeed differ.