"[...] gathering data that helps retailers build a profile then target them with offers or incentives to come back to the shop or restaurant again."
The only checkout offer vouchers that my Boots Advantage card elicited were usually for women's beauty products - says single male pensioner.
I've stopped shopping at Boots because they kept reducing their Advantage card benefits - usually announced with an Orwellian claim of "improved". Now I only shop at the local independent pharmacy - who are actually cheaper than Boots own brand items.