Nostr's inherent incentive is that it's freedom tech. Most normies just don't yet care about freedom tech.
IMO, it's a waste of time trying to convince someone by dangling an incentive they just don't care about. Instead, I would try to educate them (assuming they are at all receptive to being educated) on why they should recognize freedom tech in general as being important to them - then, convincing won't be necessary.