In my dissertation, I study factors that affect the value-creating interactions between value producers and value consumers on two-sided platforms (e.g., Freelancer and Kickstarter). In the first essay, I study how bid price dispersion affects the value-creating interactions (i.e., contracting) between service providers (freelancers) and buyers in online labor markets. I find that bid price dispersion has a negative effect on buyers' offering a contract and service providers' tendency to accept the contract if offered one. I theorize that both service providers and buyers face uncertainty over price as to how much to charge or to pay for IT services and a higher bid price dispersion leads to higher uncertainty, and thus a lower contracting rate. In the second essay, I examine the role of the lottery in value-creating interactions (namely backings) in crowdfunding platforms. I find that the lottery, when designed as an option with a participation cost, decreases backers' average contribution and the total value created for a project, albeit it incentivizes more low-value interactions (i.e., more low-value backings). I theorize that the lottery, on the one hand, incentivizes low-value interactions that would otherwise not happen, but on the other hand, transforms high-value interactions into low-value interactions. In the third essay, I study the effect of backers' online identity concealment on the value-creating interactions (i.e., backings) in crowdfunding platforms. Contradictory to a common practice that crowdfunding platforms often maintain a public list of all backers’ identity information, assuming a positive observational learning effect among peer backers, the empirical results demonstrate with backers' online identity concealed completely, campaigns on average gain more backings and money as well as become more likely to succeed. And this effect is larger for donors-those back a campaign without receiving any reward-than for rewardees-those back the campaign for the reward. / Business Administration/Management Information Systems