Invited are usually regular customers whose addresses are on file with the boutique, as well as celebrities from politics, culture and business. Collectors report consistently positive experiences with advice in the boutiques, e.g. in Bremen, Hamburg, Munich or Cologne, where special requests are also fulfilled without complication. Anyone who has lodged address data or buys regularly is also frequently invited to private sales or other special events. The new Düsseldorf boutique is located directly on Königsallee.