Utilizing novel credit card transaction data from 2020 that encompass all Korean restaurants, we quantify the restaurant-level impact of platform sales on total restaurant sales and the degree of cannibalization of other sales channels, including on-premise dining and takeout orders. We observe a robust positive effect of platform sales on total sales, with limited cannibalization effects on other sales. For each additional Korean won earned from food delivery platforms, total sales revenue increases by 0.858 to 0.965 won, while the platforms cannibalize between 0.035 to 0.142 won from other sales. Notably, while the extent of cannibalization varies by restaurant type, substantial sales growth is observed across all restaurant types.