Frank Jones is a college student who had a plow attached to his jeep so he could earn extra money plowing during the winter. Jones was under contract to plow the driveways of Mr. Washington and Ms. Adams, two neighbors down the street. John Smith lives between Washington and Adams. Jones took it upon himself to plow Smith's lot the seven times this past winter when there were storms and when he plowed the other two lots. Smith had never spoken to Jones about it, and Jones never objected. In the spring, Jones personally appeared at Smith's house and presented him with a bill. Smith refused to pay Jones, stating that, "he never agreed to any contract." That statement was made after Jones presented him with a bill of $600, which he calculated as the reasonable value of his services. After Smith's obnoxious response, Jones yelled: "I will see you in court!"
What legal arguments could Jones make to enforce his $600 bill? What legal arguments could Smith make to avoid liability?