HotelPlanner.com is the best and most popular hotel group reservation website where you will get the lowest prices per room. The website's policy is to beat their competitor's prices even at the lowest rates to ensure ongoing client satisfaction.

1. Briefly describe your hotel reservation needs in parameters like destination city, number of rooms, room type, hotel target stars, maximum cost per night, number of nights and check-in date using the online form
2. HotelPlanner.com will distribute your request to matching hotels in their database
3. Then, hotels will directly contact you (usually in minutes) while trying to beat the batch price offers of other competitor hotels
4. Ensuring you get the best rate, you choose your hotel and group rate.
5. Group members can book and pay separately if needed.
   
6. You can additionally get cash rebate and/or free room for group coordinator

Overall, HotelPlanner.com is all about finding the best hotel room rates for your special group events like weddings, charity events, holiday&birthday parties, sports team, corporate travels and meetings by applying a well-thought bidding strategy.They are in group travel reservations business since 2003 and positions as market leader.

p.s : They also operate on group car rentals, group flight quotes and batch ticket bookings sector. Be sure to check them before making your final purchase with an hotel or other travel ticket related agency.