One company legally owns every .com. And it's allowed to raise the price.

Verisign's moat is a government contract that bars every rival from running .com.: Exclusive .com contract · Govt-sanctioned, no competitor allowed · Mandatory fee on every .com · ~159M names pay Verisign · Permitted price hikes · Up to +7% in 4 of every 6 years · ~87% gross margin · The moat is the contract

Verisign runs the .com registry under a government-sanctioned contract. The technology is ordinary; the moat is the contract itself, because no rival is allowed to run .com. Every one of the ~159M .com names pays Verisign a per-name fee, and the deal lets it raise that price up to 7% in four of every six years.

That's why the internet's most generic plumbing earns margins that rival luxury software. The product is forgettable. The contract is everything.

The strongest moat in business is a contract your competitors are legally barred from signing.