Promise, Undertaking or Commitment: Language: "offer," "promise," as opposed to "quote", "asking $30 for." Surrounding circs (joke, brag? --> courts look to what offeree reasonably understood), prior practice and relationship of parties, Method of communication: broad communications (catalogs, circulars, even shopping websites) are more likely to be solicitations/invitations for offers, and the shopper initiating the sale makes the offer (American advertising rule), industry custom
Exception: Advertising: Language that identifies who gets limited supply of goods even if there is an excess in demand IS an offer ("first come first served," or "first 10 customers")
Reward offers: are offers b/c they promise $ in exchange for performance of specific tasks. 1) self-limiting (task rewarded can only be performed once) 2) open-field (many parties -- like for med tests -- unless limiting lang of how many participants they'll take), 3) auctions: invitations, and bids are offers (but "w/o reserve" = offer to sell to highest bidder)