Every interaction online can involve a dopamine hit, depending on the receivers need for external validation. A zap provides a much larger dopamine hit than a like because a scarce resource is being issued.

I don't see a like online as much different to an encouraging word or a thank you IRL. The big difference is the scale & the cost involved.

I think the existence of zaps depreciates the dopamine hit from a like.

Likes are nice, but have you ever been zapped?