There is currently a good Euro2020 offer in William Hill betting shops. On certain specific match coupons involving the Home Nations teams if £10 is bet on coupon a free bet voucher is given, either £10 or £5 depending on location of shop. for use on the self-service shop betting terminals.
Shops where there is competition from other bookies a £10 voucher is given. Shops where there is no competition a £5 voucher is given.
I've been around a few of the £10 voucher shops! It's quite profitable.