Most online marketplaces are peer-to-peer. Credit ones, however, are not and they have resurrected many features of traditional financial intermediaries. To understand why, we use online credit as a laboratory to investigate the value of financial intermediation. We develop a structural model of online debt crowdfunding and estimate it on a novel database. We find that abandoning the peer-to-peer paradigm raises lender surplus, platform profits, and credit provision, but exposes investors to liquidity risk. A counterfactual where the platform resembles a bank by bearing liquidity risk can generate larger lender surplus and credit provision when liquidity is low and lenders are risk averse.