If you are a biker, or you have loyalty to a specific theme, brand or cause, then wearing biker jacket patches could be a good way to show off your affiliation and express yourself. You don’t even have to be a biker to wear those patches, although many people are, or at least have an association with someone who is. The patches act like a “uniform” to allow people to identify each other and are an unspoken symbol of who you are and what you are friendly towards.
Patches are affordable and can be picked up at bike stores, rallies, and online. They are fun, quirky, and good for sewing on to jackets, leathers, bags, cargos and other items. Think of them as being like tattoos that you can change.
Jacket patches can sometimes be exclusive – limited runs only for club members, but sometimes they are more common and act as a symbol of fandom. Even then, fandoms can be niche, and there is a sense of closeness and exclusivity amongst those who are members of the same fandom, no matter how large or mainstream that group of fans is in truth.