Keyword cannibalization
Cannibalization occurs when several pages on the same site — or sites within the same group — target the same query. They compete for the same ranking slot, dilute link signals, and leave the engine uncertain which to surface.
In practice
Symptoms: positions that alternate between two URLs, rankings stuck below a ceiling. Fixes: merge pages, differentiate intents, or redirect the weaker one. The issue applies across sister sites too — we deliberately separated the keyword universes of primapagina.fr and pageoneboost.com so the group never competes against itself.