What is that free bet actually worth?

How the number is worked out

A free bet is a "use it or lose it" voucher: stake it and you keep the winnings, but the stake itself never comes back, and if the bet loses you get nothing. On its own that's a coin flip. Covering the opposite outcome on a prediction market removes the flip, because one of the two legs always pays.

The trick is sizing the cover so both branches pay the same. For a free bet where the stake isn't returned, that lands on a formula clean enough to do in your head:

• Shares to buy = stake × (odds − 1) — the exact amount the free bet would win.
• Cover cost = shares × cover price.
• Locked profit = shares × (1 − cover price).

With a €50 free bet at odds of 4.00, the free bet would return €150 in winnings. So you buy 150 shares of the opposite outcome. At 75¢ they cost €112.50, and they'd pay €150 if that side wins. Either branch leaves you €37.50 up: if the promo bet wins you collect €150 and lose the €112.50 cover; if it loses, the shares pay €150 against the same €112.50. That's 75% of the free bet's face value, turned into money you can withdraw.

The skill isn't picking winners. It's sizing the cover so both outcomes pay the same — and placing both legs before the prices drift apart.

What the fair price tells you

Bookmaker odds imply a probability: at 4.00, the outcome you backed has an implied 25% chance, so the opposite outcome is implied at 75%. That 75¢ is the fair cover price — the price at which the two venues agree exactly. Pay less than fair and you keep more of the free bet; pay more and you keep less. The calculator shows fair price next to your actual price so you can tell a good match from a bad one before you commit anything.

This is also why retention lands in the 70–85% range rather than at 100%: you're giving up the difference between the bookmaker's odds and the market's price, and bookmakers price promos on outcomes where that gap works in their favour.

Qualifying bets are the other half

Most promotions ask for a qualifying bet first — your own money, at your own risk, to unlock the free bet. Cover that the same way and the loss shrinks to small change: switch the toggle and the calculator prices it as a cost, so you can check the free bet is worth more than the bet that unlocks it. If it isn't, the promo isn't worth doing.

Questions people ask

Do I need the full cover amount in cash?

Yes, and it's the biggest number on the page — usually several times the free stake. It isn't a cost: it comes back when the market resolves, along with the profit. But it has to be available while the position is open, which is the real constraint on how many promos you can run at once.

Why cover on a prediction market instead of a betting exchange?

You buy the opposite outcome directly at a transparent price, with no commission skimmed from winnings, and it settles automatically. The trade-off is wording: the market resolves on its own terms, so the one thing to check is that both venues describe the same outcome. The full guide covers that.

Does amparo do this for me?

It finds the market that matches your promo across an aggregated board — Polymarket, Myriad, Azuro and Limitless — sizes the hedge, shows the locked result before you commit, and signs the cover in your browser on your own keys. Pricing a promo is free; placing the hedge is part of a membership.