There can be a number of possible causes for data not being delivered to Subscribers:

•  The table is filtered, and there are no changes to deliver to a given Subscriber.
•  One or more agents are not running or are failing with an error.
•  Data is deleted by a trigger, or a trigger includes a ROLLBACK statement.
•  A transactional subscription was initialized without a snapshot, and changes have occurred on the Publisher since the publication was created.
•  Replication of stored procedure execution for a transactional publication produces different results at the Subscriber.
•  The INSERT stored procedure used by a transactional article includes a condition that is not met.
•  Data is deleted by a user, a replication script, or another application