GOVERNING LAW Here, the subject matter was real property; thus the common law governs. FORMATION ISSUE Whether Bill’s email to the seller stating he would like to purchase the 7th Street home for $750,000 constituted a valid acceptance of an offer, thereby forming a binding contract. RULE A valid contract requires mutual assent, which consists of a clear offer and an acceptance. ANALYSIS Here, advertisements and online listings are typically not offers because they lack the intent to be bound by any single person who sees them. Instead, they are invitations for potential buyers to make an offer. Furthermore, Bill’s email on August 1st was actually an offer, not an acceptance. Bill manifested his willingness to buy the property for the listed price. At this point, the power of acceptance shifted to the seller. The seller did not accept Bill's offer. Instead, the seller stated the house was no longer available and suggested a different property on 5th Street. This response functioned as a rejection of Bill’s offer. Thus, there was no mutual assent consisting of a clear offer and acceptance. CONCLUSION Bill and the seller did not form a valid contract. There was an invitation to make an offer, not an offer itself. Without a valid offer, no acceptance was possible, and mutual assent was never achieved.