There are many reasons why your real marketable talent isn't instantly recognisable to you i.e you may be a generalist wearing many hats, your personality, existing skill set etc.
Your issue is the same issue many businesses face- finding the right niche with the highest commercial return. My advice is to investing in yourself as you would a business. Talk to seasoned experts that have managed many team members- they will give you immediate insights into your marketable talent AND talk to a recruiter- their job is to "package" and "market people- even if you don't see it a good recruiter will.
This is a starting point to give you valuable insights into the demand for YOUR talent. Once you have clarity on your individual talent THEN you can focus on all the experts and digital resources that will help you be successful at it! :)
Ps. I own a digital consultancy firm and a headhunting firm happy to wear both hats and provide advice so you can hit the success button quicker!