Identifying potential key point-of-sale (POS) customers is an important problem in banking customer acquisition. To solve this problem, a financial network is constructed based on the relationship of the merchants who use a POS in a commercial bank using our large-scale data set of the transactions made by the bank’s credit card customers. It aims to prioritize merchants in terms of the importance for the card customers based on the transaction volume and the profitability of the card customers. We aim to evaluate the merchants better in acquiring potential POS customers, increasing share-of-wallet in existing merchants, and activating inactive ones. With the evaluation of current and potential POS customers based on the value they create for the payment system, the bank’s corporate marketing and acquisition resources are used more efficiently. This study uses a large data set of card transactions to create a corporate network, and their potential value is calculated using their network centrality. As a result of this project, by knowing the customer values quantitatively, better portfolio management for existing customers and determining the right steps to acquire new POS customers are aimed.