I have used Ad-Aware for a number of years. I understand and appreciate your need to make money from this (and other) applications. I like the product.
That said, I have some problems with the direction you are taking with the product.
You can not get to the download of the free version without going through the offer to provide it free if you commit to a concurrent purchase of something else. If you say no to this, you wind up in another place that requires you to make the same decision. Not acceptable. Note that if the user has protective software running, the process of noticing and rejecting the offer is not real clear.
Your paid versions add anti-virus. There are no lower price versions for improvements in function for anti-spyware, which is a primary reason one would have Ad-Aware in the first place. I am not interested in upgrading for anti-virus. Lots of vendors are in this market, and I prefer other solutions based on the user feedback available online.
You have no obvious process to find out what the current version is that your are downloading. No way to determine if it is newer than what is installed. The file names you post for download need to have the version number embedded. The text leading up to the download needs to have the version number prominently displayed.
Please, in your effort to make money, don't ignore the freeware users that have used your software, and established your credibility, over a long period of time.