Product assortment is of significance importance to omnichannel fashion products vendors. These vendors must make assortment decisions well ahead of their selling season and across channels that face distinct types of demand and comprise different fulfillment capabilities. Because of differences in operational costs and margins across channels, assortment decisions are likely to affect vendors’ top and bottom lines, ultimately affecting their profitability. In this book chapter, we use data from an omnichannel fashion product vendor to empirically assess the likelihood and the sales volume of a product according to its characteristics in two channels, wholesale and dropshipping. Establishing demand profiles based on fashion product characteristics allows vendors to evaluate jointly channel choice and stocking decisions for assortment integration across multiple channels.