IKEA hotels. Given the commoditized status and lack of differentiation of many hotel chains like Hampton Inn, Fairfield Inn, Red Roof Inn, Motel 6, Comfort Inn, etc., imagine if a particular chain partnered with IKEA to decorate their rooms with simple, clean and comfortable bedroom furniture. This fact alone would give that hotel chain a significant point of differentiation. The hotel chain also gets the economic benefit of furniture at prices that are even better than wholesale prices on generic furniture. IKEA gets significant "consumption-experience level" exposure to target customers at a fraction of the expense of TV ads or building vast new retail stores.
Consumers get to experience IKEA furniture "in action" which undoubtedly would give them enough first-hand experience information to make future purchase decisions. Finally, some creative "consumer insights research" opportunities can even be built in, such as allowing visitors to select from among differently decorated IKEA hotel rooms and tracking such decisions to gather which items are most popular or even how to make IKEA's in-store bedroom sets more appealing.
In summary, both the hotel and IKEA achieve "experiential marketing" which drives greater marketing effectiveness (i.e. hotel chain differentiates themselves from others; IKEA lets customers actually experience their products prior to going to a store), delivers a more impactful experience to customers, and even reduces costs for both parties.