What is the theme in Rule 34 by Charles Stross?

Spam vs advertising is a theme in this book. Spam is a form of advertising that evolved as a result of the creation of the internet. It is a virtual free for all that allows anyone anywhere to sell anything and it is a growing force in the every changing technological world. In fact, spam has become the vehicle of choice for criminals world wide. Now they can operate with impunity, hawking their wares or services with little consequence or conflict. Spammers can create virtual offices, and even virtual communities that are untraceable by the average citizen. With the use of net bots, they can send bulk, anonymous emails world wide and the software created to weed out this form of advertising is constantly in a state of catch up. This leap in technology makes regular advertising a thing of the past.