Free sampling, which has been widely applied and studied in marketing, has recently been adopted by entrepreneurs on crowdfunding platforms. Using a dataset from a unique crowdfunding platform, we study whether opting to provide free samples to potential backers increases the likelihood of a campaign meeting its goal. We also investigate how free sampling influences the fundraising dynamics. Using a matched sample of crowdfunding campaigns, we demonstrate that providing free samples significantly improves crowdfunding performance. And among those projects which opt for free sampling, persuasion effect during the report period contributes to the positive effect. The higher the score from the evaluator, the more successful the campaign will be. We also find that the longer the investors are exposed to the evaluation report, the more money is raised.