A contract between a land company and real estate agents, whereby the latter agreed to sell the town lots of the company at a certain town, for such prices as might be deemed just, and the company agreed to pay the agents ten per cent. on all sales, and to set apart certain lots for advertising purposes, etc., was not invalid for lack of consideration, absence of mutuality, or want of definite term of existence. Albany Land Co. v. Rickel, 162 Ind. 222, 70 N. E. 158; Boyd v. Watson, 101 Iowa, 214, 70 N. W. 120; Norman v. Hopper, 38 Wash. 415, 80 P. 551.