A number of 0x community members have asked questions about how ZEIP-31 could potentially affect their business model or value proposition. The ZEIP-31 proposal would incorporate a fee of approximately $0.10 USD on the taker side of each trade. One important thing to communicate is that most of this fee (~75% at the outset) will be rebated to the maker side of the trade. Due to this rebate, the effective cost borne by protocol users is only ~$0.025 per order fill. Due to the small size of this fee, we do not expect ZEIP-31 to have a meaningful impact on user costs or trading volumes. This research note is a brief exploration of this issue and includes some real-world examples, which I hope will help to make the topic more approachable and easier to understand.