Thinking out loud here: I'd say reactions are just another form of a reply, like a text but short and sweet and supposed to be fun. Zaps are a nice addition but since it's based on scarcity may influence people to treat it more as a store of value, and hence any tipping would be more valuable. That said, zaps are a good way to support someone you support, like an artist, writer, etc. Good to keep in mind that these relationships form over time. Does that lead to zap fatigue, where you support at first but then stop? Or the creator is at the whims of changing interests and is more precarious and vulnerable to serve the interests of what gets more zaps versus what art or build projects they want to practice that may not be as popular? All interesting questions.