The Internet has enabled consumers to find basic information about many offers at very little cost. For example, databases of accommodation for sale contain information about the price, location, number of rooms and size of a flat. This allows purchasers to assess whether an offer is potentially attractive, but due to the variety of factors involved in choosing a flat (e.g. aesthetic considerations) is insufficient to make a final decision on such an important purchase. Automizing the choice of an initial shortlist using information from the Internet is a useful approach to choosing an attractive offer while constraining search costs. This article describes an algorithm that constructs shortlists of attractive offers from a database on the basis of consumers’ preferences. The length of the shortlist is set by the user. Such shortlists can be treated as a list of flats to be physically viewed or as an initial step in defining such a set. This algorithm can be applied in a range of scenarios, e.g. an employer wishing to hire a specialist employee.