if you have the benefits from bitcoin? you can promote bitcoin in many ways.
-By explaining bitcoin to others, spread the word about bitcoin and take note you must learn more about bitcoin to do this.
-If you have skills in blogging, design, video and photo editing, web design, etc. Create something different out of your skills to promote bitcoin.
-If you have business establishment try to experiment to accept bitcoin currency.
if you have any idea how to promote bitcoins just share here.
Maybe OP wants to know how to promote a product OP asked how to promote it.
If you want to promote, social media can be the place for promotion, or you can hire a famous actor/actress who can help you to promote if you want to be quickly recognized by people.