Wikipedia's definition of Wiki vandalism includes "Spam, the insertion of irrelevant links for commercial purposes only."
Since there is now such a thing as splog, I'd like to propose the Neologism Swiki, meaning a form of Wiki vandalism in which the vandal inserts irrelevant links for commercial purposes only.
A good example of this is Wikipedia's supply chain article. This page was updated with spam links to a well-known software vendor at least twice in September.
And I thought they were a class company! Lord knows, I'd never do that!