From my experience with PayPal Working Capital, you get loaned $X based on a percentage of your expected annual sales, and must pay back Y% up to a maximum of $

From my experience with PayPal Working Capital, you get loaned $X based on a percentage of your expected annual sales, and must pay back Y% up to a maximum of $Z. There's no additional upside for PayPal beyond the lofty rates they charge for the service. The fee is also "fixed" and is based on an APR calculated at the time of application. You never accrue interest.