People tend to utilize multiple social network sites (SNSs) simultaneously to maintain some social relationships, which results that there are many overlapping relationships and interactions among SNSs. Although many studies have focused on social interaction and cross-SNS user footprint analysis and understanding, little research investigates social interaction from a perspective of two or more SNSs, and the interplay of interaction among SNSs has been unknown. In this paper, we aim to explore whether interaction building in a new SNS hinders the interaction frequency in an existing site, and if so, what kinds of users and relationships’ interactions are more or less likely to be affected. For these questions, we sampled 7,015 pairs of overlapping identities, 23,590 pairs of overlapping relationships and 6,771 pairs of overlapping interactions from Weibo and Douban and made analysis by combining multiple methods like Regression Discontinuity Design and Random-effects Negative Binomial Regression model. Our results suggest that no matter from the perspective of individuals or from the perspective of relationships, interaction construction in a new SNS is detrimental to interaction frequency in an existing site. Based on our findings, we also propose several valuable insights about how to enhance social interaction and promote its retention when users are involved into interacting practice in multiple platforms.

人们倾向于同时利用多个社交网站（SNS）来维护一些社交关系，这导致SNS之间存在许多重叠的关系和交互。尽管许多研究集中在社交互动和跨SNS用户足迹的分析和理解上，但是很少有研究从两个或多个SNS的角度研究社交互动，而且SNS之间互动的相互作用尚不清楚。在本文中，我们旨在探讨在新的SNS中建立交互是否会阻碍现有站点中的交互频率，如果是，则什么样的用户和关系的交互或多或少会受到影响。对于这些问题，我们抽样了7,015对重叠身份，23,590对重叠关系和6个样本，来自微博和豆瓣的771对重叠相互作用，并通过结合回归不连续性设计和随机效应负二项式回归模型等多种方法进行了分析。我们的结果表明，无论是从个人的角度还是从关系的角度来看，新SNS中的交互构建都不利于现有站点中的交互频率。基于我们的发现，我们还提出了一些有价值的见解，涉及当用户参与多个平台的互动实践时，如何增强社交互动和促进其保留。我们的结果表明，无论是从个人的角度还是从关系的角度来看，新SNS中的交互构建都不利于现有站点中的交互频率。基于我们的发现，我们还提出了一些有价值的见解，涉及当用户参与多个平台的互动实践时，如何增强社交互动和促进其保留。我们的结果表明，无论是从个人的角度还是从关系的角度来看，新SNS中的交互构建都不利于现有站点中的交互频率。基于我们的发现，我们还提出了一些有价值的见解，涉及当用户参与多个平台的互动实践时，如何增强社交互动和促进其保留。