Abstract. A very common approach in chemistry and biology is to observe the progress of an experiment, and take the result of this observation as the final output. Inspired by this, a new approach to computing, called system/observer, was introduced in [3]. In this paper we apply this strategy to sticker systems, [8, 11]. In particular we use finite automata (playing the role of observer) watching the “evolution” of a sticker system and translating such “evolution” into a readable output. We show that this way of “computing by observing” brings us results quite different from the ones obtained when considering sticker systems in the standard manner. Even regular simple sticker systems (whose generative power is subregular) become universal when considered in this new framework. The significance of these results for DNA computing (by sticker systems) is briefly discussed.