New Zealand's Smokefree 2025 goal aims to greatly decrease the availability of tobacco. One option is to cease the sale of tobacco from convenience stores. However, tobacco companies and retail trade associations oppose this move and have argued that customers who purchase tobacco drive footfall and spend more than non-tobacco customers. The aim of this study is to test the validity of industry claims about the importance of tobacco to convenience stores. During November and December 2019, immediate postpurchase surveys were undertaken with customers on exit from a random sample of 100 convenience stores in two New Zealand cities. We estimated the mean number of items purchased, including tobacco and non-tobacco items, and mean expenditure on non-tobacco items. Of the 3399 transactions recorded, 13.8% included tobacco, of which 8.3% comprised tobacco only and 5.5% included tobacco and non-tobacco items. The mean number of transactions containing both tobacco and non-tobacco items was 1.98, and 1.87 for those containing non-tobacco items only. Customers who purchased tobacco and non-tobacco items spent on average NZ$6.99 on non-tobacco items, whereas customers who purchased non-tobacco items only, spent on average NZ$5.07. Our results do not support claims that tobacco drives one-quarter of footfall into stores or that customers who purchase tobacco spend almost twice as much as non-tobacco customers. Combined purchases of tobacco and non-tobacco items constituted 5.5% of transactions; the impact on a store's profitability of removing tobacco sales is unknown and could be the focus of future research. © Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.