AbeBooks initially offered its services for a flat listings fee, based on the number of titles listed for sale. The model was changed in the early 2000s to include a commission on sales. In April 2006, AbeBooks started mandatory processing of MasterCard and Visa credit card transactions on behalf of its sellers and added a 5.5% charge for the provision of this service: previously this service had been optional. In 2008, AbeBooks started charging a commission of 13.5% on the cost of postage as well as the book price. Currently (2013) the commission charge is set at 8% of postage and book price.