Under the terms of the deal, created by partnership marketing agency Cocktail Marketing, QS customers who spend over £15 in store will receive a free Mills and Boon novel as well as a voucher for WHSmith.
QS will also display Mills & Boon branding on till posters, display units and leaflets.
The partnership will start in November and run until Christmas. Cocktail Marketing matches brands to achieve marketing and sales objectives at a lower cost and without the need for advertising. Existing clients include the Discovery Channel, The Evening Standard, GMG Radio and play.com.
Cocktail is also an official roster agency for the Central Office of Information (COI), EnjoyEngland.com and VisitBritain.com.