Mo. Rev. Stat. § 407.700

"Home solicitation sale" means a consumer credit sale of goods, or services, except the sale of real property or interest therein, or the sale of personal property which is incident to the sale of real property or interest therein, in which the seller or a person acting for him engages in a personal solicitation of the sale at a residence of the buyer and the buyer's agreement or offer to purchase is there given to the seller or a person acting for him. It does not include a sale made pursuant to a preexisting revolving charge account, or a sale made pursuant to prior negotiations between both parties present at a business establishment at a fixed location where goods or services are offered or exhibited for sale.