marketer, seller, trafficker, vender, vendor - someone who promotes or exchanges goods or services for money

adman, advertiser, advertizer - someone whose business is advertising

sell, trade, deal - do business; offer for sale as for one's livelihood; "She deals in gold"; "The brothers sell shoes"

bargain down, beat down - persuade the seller to accept a lower price; "She beat the merchant down $100"

bargain, dicker - negotiate the terms of an exchange; "We bargained for a beautiful rug in the bazaar"