a sprat to catch a mackerel
01
*If you describe something you do as a sprat to catch a mackerel, you mean that it involves a small cost or amount of effort but it will bring you great rewards or benefits
Dialect
British
British例
Sure you need to have free content—you hook people on the free trial, that's how you get them to pay for an annual subscription. It's a sprat to catch a mackerel.
