An NBA may determine that it is appropriate to offer a mixed portfolio of free and priced services depending upon the resources required to deliver them. For example a basic offering of an online Web catalogue might be made freely available while individually tailored or added value services to specific users could be priced. Alternatively embargoes may exist for records licensed from commercial third parties that prevent their being offered freely until a specified period has passed. The financial and political environment surrounding in which the NBA operates will inevitably determine the range of options available in this area.