For several years we've had advertising on technology-related sites. But many of our sites aren't about technology at all, so we haven't sold ads for them. That hasn't been a hardship since Stack Exchange sites require only a small investment from the company to set up and keep live. Thanks entirely to the efforts of your community, this site has become an amazing resource on the internet. Generating revenue from non-technology sites will enable us to dedicate more resources to meeting your needs so this is good news.
The test starts May 21 and our advertising team will be monitoring to see how ads are performing. We don't know how many ads will run on this site. It could be just a few or a bit more. In either case, these ads will be carefully vetted and we'll be keeping watch to continue to provide good content.
If you see any ads that are inappropriate or have any questions about this experiment, please let me know by starting a new question and tagging it with advertisements. This is a work in progress and we are expecting a time of learning and refinement as we move forward.