Screenshot of what I mean:
https://commons.wikimedia.org/wiki/File:Inline_donor_bannerbass.png
Inline ads are generally considered to be something that gets into scummy advertising territory (for example even adblock plus's rather questionable Acceptable Ad policy doesn't accept them).
On a related note the FAQ appears to be out of date:
https://wikimediafoundation.org/wiki/FAQ/en
Unless we are still in the 2015-2016 fiscal year.