very good offer from denise, sadly it's invitation only and tiered for up to 5,10,25 and 50 depending on how much of a degenerate you are. mine came through as below so check your emails if you have an account with them.

Cheltenham Free Bet Offer

The Cheltenham Festival runs from Tuesday 13th to Friday 16th March - and we’re giving you a Free Bet on the stand-out race each day (up to £50 maximum) when you place a single bet on any other Cheltenham race that day. T&Cs apply.

Cheltenham Festival Free Bet races:

Race Day/Time Qualifying Bets Count From
Champion Hurdle Tuesday 13th March (15:30) Monday 12th March (13:00)
Champion Chase Wednesday 14th March (15:30) Tuesday 13th March (13:00)
Ryanair Chase Thursday 15th March (14:50) Wednesday 14th March (13:00)
Cheltenham Gold Cup Friday 16th March (15:30) Thursday 15th March (13:00)

How to take part:
• Place a single bet on any Cheltenham race each day other than the Free Bet race stated above.
• You will then receive a Free Bet on the selected Free Bet race, equal to the value of your largest single bet on any other Cheltenham race that day (max Free Bet value £50).
• Your qualifying bet must be placed between the time stated above and the start of the relevant Free Bet race. Ante-Post bets, Tote/Pari-Mutuel (bets and dividends) and Specials markets located within the Cheltenham Festival Specials 2018 section will not count for this offer.
• Once placed, confirmation of your qualifying bet will be displayed on the bet slip as well as in My Bets and History.
• To use your Free Bet, simply add your selection for the relevant Free Bet race to the bet slip, and choose the 'Use Free Bet' option next to that selection.