Ads have been around for a long time on B&B. The forum costs money to run and this is one way to pay for the upkeep. Due to a configuration error with the most recent update they were not displaying correctly, or in some cases, at all.
This has been fixed and the ads are working correctly once again and how they always have in previous software versions. One way to stop seeing ads is to become a contributor which also helps with running costs.
I'm not sure when they began, but I am seeing popup ads while logged into B&B. Was there a recent change to our forum - used to be members when signed in didn't get the snake oil sales pitches? Or is there a setting I've in"ad"vertently tripped after a dozen years here?