A monopolist data seller designs and sells signals about borrower quality to competing lenders. Optimal signals raise lenders' profits, and hence seller revenue, by softening lending competition through two channels. Segmentation negatively correlates good grades across lenders, limiting competition for high-quality borrowers. Deterrence makes a bad grade precise enough that its recipient does not lend at all. The channels conflict: higher precision strengthens deterrence but weakens segmentation. Among all information structures, the optimal one relaxes this trade-off by carving out for each lender a distinct set of core borrowers, priced at the monopoly rate. It thus tells a lender not only whether a borrower is creditworthy but also how hard to compete. Adding lenders weakens both channels, but revenue never falls below that from informing only two of the lenders. A rival data seller cuts the incumbent's fees to a correlation premium without changing its design or the lending equilibrium.