http://www.giveawayoftheday.com offers a commercial software title everyday for free as some kind of promotion.
This script will go to their website, download the free give away and send you an email with the title and description of the software.
You typically compile this script as an executable and put it in a scheduler. When you notice an interesting software title in your mail, you simple install it for free.
Note that you have to install the free software within the day it is offered. That is how the promotion works, but it has no ads, etc.
Remember to configure your email address in the last script line before compiling.