[Buge]

It looks like currently their ads are all player-created, for their own content. For example refresh this page and see the banner at the top:

https://www.roblox.com/catalog?Category=0

But I seem to recall in the past there used to be some regular ads. For example see this archived page:

https://web.archive.org/web/20120427192637/http://www.roblox...

which has this embedded iframe:

https://web.archive.org/web/20120308000433if_/http://www.rob...

which has Adsense javascript embedded in it.

[glaring]

Correct, they used to display regular ads on their website (but never in the actual games) for those users that did not purchase the Premium subscription. Users with the premium subscription would then see only user-created ads for user-created content.

It was honestly quite jarring and this new approach is better for developers on the platform, as they can reach way more people.