Many of the readers are aware of a loyalty program called "Discount voucher."
Its promoters make great claims for it. Its critics are not so sure. A detailed and I think a fair review is available here on this blog which has not been answered by it promoters using what is the best publicly available information about the scheme.
However, Discount Vouchers are far from the only loyalty program available to a retailer. They are certainly not necessarily the best way to go. With our point of sale system, you have lots of choices. I invite to check out this video on several other options here.