Birki’s, the ecological brand of Birkenstock, has started a cross-branding campaign with Weleda, a German producer of natural bath lotions and cosmetics that also offers foot balsams and skin creams. Point-of-sale displays with Weleda testing tubes and other joint marketing materials are being presented in German pharmacies and shoe stores. Birkie is also offering Weleda products as a prize for the runner-up in a contest on its own website for the best design ideas.