Once a merchant has installed Rebuy via the Shopify app store, Rebuy JS will load in through the head of the document. By default Shopify loads all apps after the regular Shopify site has finished loading. This means Rebuy is not allowed to run until after the site has finished loading which can sometimes take 3-4 seconds or longer. This may cause a delay in load times and so it is suggested to use the advanced installation guide to help Rebuy features load in more quickly.
Optionally, Rebuy automatic installation can be disabled from Rebuy Admin and Rebuy can be installed manually.