Delta Airlines and Lyft offer one Delta Skymile per $1 spent on Lyft rides when you link your Lyft and Delta Skymiles accounts. (Not a member? It's free to sign up for both Lyft and Delta Skymiles.) Plus, earn three Delta Skymiles per $1 spent on Lyft rides to and from select airports. Some exclusions apply. The travel deal ends August 31.