This is a very popular slang term in the world of business. A kickback is usually a sum of money or something of value in exchange for business given. For example, Yuri introduces a friend Sergei as a new client to Anna, who works as a real estate agent. Soon after, Sergei buys a house with Anna's help and Anna receives a $1000 commission for the sale of the house. Anna shows appreciation to Yuri by giving him $100--hence, the kickback. Kickbacks are not always given directly as cash. For example, Yuri can also be a wine distributor and can choose any winemaker to buy from. He chose to buy 10,000 cases of wine from a smaller winemaker. As a kickback, the winemaker treats Yuri and his wife to a lavish vacation to St. Petersburg. Variants are endless. Как сказать по-русски?