What is a keyword lander?
A keyword lander is a simple page that shows a list of clickable search terms and little else. Each term leads to a page of sponsored search results. It is the classic parked-domain and feed layout. Google's current rules favour real article pages instead, so plain keyword landers are now found mostly on non-Google feeds.
On a keyword lander the first click is free and the second pays, which makes it a two-click flow. The share of visitors who click a keyword is the Lander CTR; the share who then click an ad is the Ad CTR. Multiply the two by RPC and you have revenue per visit.
With Related Search on Content, Google does not allow the unit on pages that lack standalone value, so the keyword block has to sit inside genuine content. Publishers who treat the article as decoration around a keyword block are the ones most exposed to a policy violation.