Ladbrokes, International Game Technology and Scientific Games have all announced China lottery ventures this year, but profits are far from certain for them or for a host of lesser-known companies.

• 过去10年中，彩票销售额的年均复合增长率为37%25，在去年达到105亿美元。国际企业正在争相出售技术或担任分销商，其回报通常是从销售额中分得一部分。