The purpose of inline hooks was originally for jigging, allowing the hook to run inline with the jig. However, they are now commonly used to replace treble hooks on lures. Along with being more humane, inline hooks provide a stronger connection between lure and fish due to their heavier gauge wire. When switching from treble hooks to inlines, it is recommended to go up a split ring size to match the weight. Keep in mind that results may vary and it's always best to know your lure and adjust accordingly.