A German furniture retailer shipped 270,000 orders before collecting a cent, then logged who never paid. One of the ten things it recorded about each buyer was their email domain. Hotmail addresses defaulted at 1.45 percent, Gmail at 1.25, against a 0.94 percent average. Researchers at Frankfurt School of Finance, Humboldt University and Duke published the numbers in the Review of Financial Studies in 2020, from orders placed in 2015 and 2016. The furniture arrived first and the invoice came 14 days later, so every checkout was a tiny loan. Yahoo users defaulted at 1.96 percent. T-Online, a paid German internet provider that bundles email with phone and TV service, sat at 0.51 percent. Smaller details in an address predicted just as much. Customers whose email contained their own name defaulted at 0.82 percent against 1.24 percent for those without one. Adding a number pushed it to 1.41 percent. Mistype your own address on the first attempt and the rate hit 5.09 percent. Stacking two of them widens the spread further. A Mac user with a T-Online address defaulted 0.36 percent of the time, an Android user with a Yahoo address 4.30 percent, a twelvefold gap from two facts the company already had. All ten combined beat the credit bureau score at telling payers from non-payers, scoring 69.6 out of 100 against the bureau's 68.3. The two barely overlap, correlating at roughly 10 percent. These numbers mostly track income and age rather than character. In Germany the paid providers ranked highest, and Gmail landed below GMX and two German services that charge for their better tiers, so the pecking order is local. The social pressure had a price tag. Gmail launched on April 1, 2004 with a gigabyte of free storage against Hotmail's two megabytes, about 500 times more, and enough reporters took the announcement for an April Fools prank that Google had to confirm it was serious. Accounts stayed invite-only for nearly three years. A finance professor at Southern Methodist University later rebuilt the resale market and found 63,378 invitations traded on eBay for $393,027 across three months, the first one going for $35. Hotmail was two engineers and $300,000 of venture money, launched on July 4, 1996 and sold to Microsoft eighteen months later for about $400 million. Microsoft retired the name in 2013 and moved 300 million accounts to Outlook in six weeks. Old addresses still work, but you cannot make new ones. The paper ends outside lending entirely. Once people learn their digital traces carry a price, the authors wrote, they start managing them, and you get a population that thinks twice before showing anything online. Someone has already put a number on the pressure.