Not just big customers. Here in Toronto (not in Shaw's jurisdiction, but if Shaw isn't slapped hard on this very soon, Rogers and Bell will do the same), we have Time-Of-Usage rates with smart meters. Our usage is still fairly predictable because there's three time bands, but we pay 5.9c/kWh at low price, 8.9c/kWh at mid price, and 10.7c/kWh at high price (http://www.torontohydro.com/sites/electricsystem/residential...).