Companies like eBay, Google, or Amazon offer web services that allow third parties to access various data sources and applications. This research contributes to existing literature by analyzing third parties' business opportunities that result from using eBay web services.Therefore, business models of companies that use eBay web services are studied, and the contribution of eBay web services to strategic business opportunities are analyzed. The classification theme comes from Timmers' taxonomy for e-business models. Results show that eBay web services give opportunities for start ups, and that existing companies can use eBay web services in order to obtain strategic business advantages.