Online configurators are basically everywhere. From physical goods (cars, clothes) to services (cloud solutions, insurances, etc.) such configurators have pervaded many areas of everyday life, in order to provide the customers products tailored to their needs. Being sometimes the only interfaces between product suppliers and consumers, much care has been devoted to the HCI aspects of configurators, aiming at offering an enjoyable buying experience. However, at the backend, the management of numerous and complex configuration options results from ad-hoc process rather than a systematic variability-aware engineering approach. We present our experience in analysing web configurators and formalising configuration options in terms of feature models or product configuration matrices. We also consider behavioural issues and perspectives on their architectural design.