As you all know, advertising is an important source of revenue for Stack Overflow and it helps us support all the sites across the Stack Exchange Network and the resources that go into maintaining and improving the experience on the platform. We are going to be introducing middle sidebar ads, which have been on the main Stack Overflow site for years, to some of the tech sites including Drupal Answers.
The middle sidebar ads have the same standards as any other ads on the platform. Ads are non-intrusive and static. Ads go through a vetting process to ensure they are appropriate for the communities on Stack Exchange. If you see an ad that may not follow our established standards and guidelines, you can let us know by using the "report this ad" functionality. Here is a mockup of what these will look like when two ads are showed (the existing ad placement and the new middle sidebar ad placement):
This ad space won’t be available for display until May 10 because we wanted to give you a heads-up before you started seeing them. Ads are an essential line of business for us and we’re committed to giving you advanced notice whenever we introduce a new form of advertising on the network sites. If you have any questions or concerns, please let us know.