How do you encourage people to join your frequent guest loyalty program when you don’t have points to give away? Easy, just give away miles.

With Omni Hotels’ “Double Without the Trouble” Sweepstakes, legal residents of the 48 contiguous United States (except Florida) and the District of Columbia who join Omni’s Select Guest program will earn the chance to double their American AAdvantage, Delta SkyMiles or United Mileage Plus miles.

Just join the program (between July 1 and Aug. 31). That’s all you have to do. That, and be at least 25 years old.

One Grand Prize winner will be selected in a random drawing on Sept. 8 from all qualified entrants, and that winner will get to see their miles doubled in any one of the programs listed above — up to a maximum of 500,000 miles.

To join the Omni Hotels Select Guest program and enter your name into the drawing, go to http://www.omnidoublemiles.com.