This data comes from the Facebook Ad Library report, which Facebook provides as part of its transparency efforts.
It's all a bit messy because Facebook does not appear to put any effort into making this efficient or simple and actively seems to avoid making it accessible outside of their own, rather horrible, API. You can access the Library directly but then you have to manually build a search each time you use it.
That said, the Facebook data does provide far more depth than the equivalent Google data.
This gadget allows you to search total spend on Facebook since 4 August 2020 to the beginning of the current month.
Nothing here should be taken as any sort of endorsement from, or relationship with, the enormous companies involved. Company names are their trademarks. Etc, etc.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
This is offered entirely 'as is' and should not be relied upon for any decisions of any sort.
Note: We return max 500 results.