The factors that influence product development depend, amongst other things, on the type of product, the economic situation, the state of the art technology and various social and cultural trends. In modern era, often not the specs and costs are the decisive factors for purchasing a specific product, but aspects like design and brand personality. One of the reasons for this is the abundance of products of the same type for the same purpose. In fact, this is the current situation for dry powder inhalers (DPIs) although the self-congruity concept seems more applicable to the doctors who prescribe the inhalers than to the patients who are using them. For the early DPIs from the 1960s and 1970s the driving factor for development was the necessity of having an alternative for cholofluorocarbon (CFC) containing metered dose inhalers (MDIs). An important factor affecting their design could have been the desire to improve pulmonary drug delivery compared to that from MDIs, but unfortunately this oportunity was missed. Instead, available technology like hard gelatin capsules and adhesive (‘ordered’) mixtures were used and lung deposition remained more or less the same as from MDIs (only approx. 10% of the dose). After the capsule (and multi-dose reservoir) DPIs became more widely accepted and patents on inhaled drugs expired, consulting groups and generic manufacturers became more and more involved in the emerging DPI market, purely on an economic basis. This does not mean that there have not been developments yet aiming at improvement of the therapy with DPIs and various future applications may give a boost to using new technology for dry powder inhalation.