J. crew teaming up with several famous brands, including belstaff and timex, to offer exclusive products in the j. crew stores and on its website is an example of

What J. Crew, Bellstaff, & Timex are doing is a type of marketing promotion called cross-promotion.

Cross-promotion is done by promoting a product using another product or service's promotion. This type of promotion is perfect when the customer base between the two products are alike, thus reducing the cost needed to promote two products by just using one promotion instead.