The subject of this research is to find out the most suitable of opaque selling strategy without diluting hotel brand and pricing policy to be implemented in Klikhotel.com, an Indonesian-based online travel agent (OTA). The starting point of the research is a literature study in opaque selling theory, roles of OTA, and behavior study of Indonesian online market. It is followed by choosing a potential opaque selling mechanism and analyzing OTAs which have applied this mechanism. After analyzing similar systems, an adapted system is created for the current system of Klikhotel.com. It is used as a simple test market to measure the feasibility of a new product from customer’s perspective. We design a system that is less opaque to adjust the Indonesian market that still require photos and reviews in decision making prior to booking a hotel. Our design results in an additional tool in the Klikhotel.com extranet system which called 'mystery hotel' promotion, whereas for the customer module, we design that the opaque hotels displayed in a higher position than the non-opaque one to increase conversion rates. The opaque selling mechanism using this posted price strategy has been tested to Klikhotel.com current customers and has shown a positive result.