Some find bridal registries inappropriate as they contravene traditional notions behind gifts, such as that all gifts are optional and delightful surprises personally chosen by the giver, and that registries lead to a type of price-based competition, as the couple knows the cost of each gift. Traditionally, weddings were considered a personal event and inviting people to the wedding who are not known to at least one member of the couple well enough to be able to choose an appropriate gift was considered inappropriate, and registries should therefore be unnecessary.[39] Whether considered appropriate or not, others believe that weddings are opportunities to extract funds or specific gifts from as many people as possible, and that even an invitation carries an expectation of monetary reward rather than merely congratulations.