Social media has provided both companies and customer with new opportunities. Customers are increasingly integrating social media into their daily lives and companies has noticed these new traditional medias and started to take advantage of them through brand communities. The new behavior occurring on brand communities is what research call customer engagement behavior and goes beyond transactional behavior. However, customer engagement has not been fully researched on different social media platforms. The most researched platform to date is Facebook. And with the rapid growth of social media and the constant development of new platforms it is of importance to understand customer engagement behavior on different social media platforms to further being able to adapt to each unique platform. Purpose: This study aimed to investigate the frequency of customer engagement behavior and its affect on perceived relationship benefits and ultimately, relationship outcomes. This based on three different social media platforms where one company were present with brand communities and then compare the outcome of each platform with each other. Hypothesis: 𝐻1 = The frequency of customer engagement behavior leads to perceived relationship benefits of engaging in a brand community. 𝐻2 = Customer perceived relationship benefits have a positive effect on relationship outcomes. Methodology: Cross-sectional online questionnaires distributed on three different social media platforms – Facebook, Instagram, and Pinterest. Analysed using linear regressions. Findings: The findings indicates that the frequency on which a customer engage in engagement behaviors showed no statistical significance on Facebook, however, the frequency of reading messages, visiting the brand community, and purchasing products did show statistical significance on Instagram. Furthermore, the perceived relationship benefits that showed significance for both Facebook and Instagram was practical and economic benefits. While on Facebook social enhancement was considered an important indicator for relationship outcome and entertainment