The Real Deal looks at the relationship between auction houses and the real estate firms they refer clients to. Though the story claims few transactions result from the referrals for either Christie’s or Sotheby’s:

“Sotheby’s provides meaningful brand visibility,” said [former head of SIR in New York, Stuart] Siegel, “but it doesn’t translate into meaningful or definable percentage of sales.”

Nonetheless, for Sotheby’s the relationship has been a meaningful driver of both revenues and positive brand recognition. Sotheby’s International Realty—or SIR, as it is known—was started in house at the firm in 1976.

In 2004, CEO Bill Ruprecht sold the division to Realogy Holdings, a real estate brokerage conglomerate, for $100m plus a royalty on franchises and sales:

That licensing deal earned Sotheby’s $7.2 million in fees in 2014, according to the company’s most recent proxy statement, up from $6 million in 2013 and $5 million in 2012.

Not only is that free money to Sotheby’s, the SIR offices, brokers, signs and publicity for transactions all constantly reinforce Sotheby’s status as a luxury brand without the firm having to pay for the privilege. In fact, that deal may do more to establish Sotheby’s brand reputation in the non-art-buying public’s mind than any of the marketing the auction house does.

Sotheby’s International Realty  (Brown Harris Stevens)