Toothbrushes, ice-cream and frozen pizza: data reveals how Coles and Woolworths switch promotions in sync | Supermarkets

You’re looking to buy an electric toothbrush. You’re in Woolworths and you see one of the Oral-B kits advertised for sale at $99.50.

The product appears to be a half-price bargain, reduced from its usual price of $199, which also happens to be how much the same item costs at Coles.

But what…