I know we were still quite a bit away but so far I am seeing for the first day alone.
WH - £10 refund if your horse finishes 2nd in any race
Skybet £10 free bet if your horse loses first race of the day
Virgin Bet - Money back as a free bet if your horse finishes 2nd, 3rd or 4th on every race
PaddyPower - Money back as a free bet if your horses finished 2nd, 3rd or 4th on every race
Betfair Exchange - Bet £20 get £20 free bet - This is on the 1st race and you need to place your bet after Sunday 8th March 11 am
Lots more time for other offers to appear but I'd say there's around £100 there alone right now you can grab if you have a decent bankroll and can place lots of bets throughout each day!