The crowd of more than 100,000 that saw Shackleford win the 136th running of the Preakness Stakes (pictured left) was in many ways an isolated affirmation of the strengths of racing in the US. Betting turnover in Maryland has fallen by a third in the past five years, part of a national decline in interest in a sport where wagering is tightly regulated and the parimutuel system, where winning bets are paid at odds relating to the pool size, dominates betting. Read more

Betfair, the UK-based online betting exchange that went public last month and reached a valuation of more than $2bn, is looking to the US and California in particular for future growth.

David Yu, chief executive, who grew up in the Bay Area, returned to San Francisco this week for the Web 2.0 Summit, where I spoke to him on the sidelines about Betfair‘s US plans. Edited highlights after the jump: Read more