This paper is concerned with an empirical context where uncertain incentives are widely used in motivating customers’ online behavior such as generating and spreading online word of mouth. Using a data set scraped from Sina Weibo, this study takes a first step in examining the effects of weibo lotteries on the customer’ engagement activities, defined as Likes, Comments and Reposts.

The main findings are (i) weibo lotteries can be very effective in promoting more customer activities under the lottery tweet; (2) the increases in customer engagement activities are directly and most strongly boosted by the lottery’s entry requirements; (3) weibo lotteries have significant positive carryover effects on the customer engagement activities with respect to subsequent regular tweets by the same user.