Sounds like a saturated space, but folks are always interested in quality, free, sports commentary and journalism.

Presumably your betting tips are based on some competent insight which is not universally available. Write about that.

If your writing is good, you can find an outlet for it, like a message board site. So, start writing frequent, quality posts, with in-depth information, based on your research.

In this way, you'll gain a reputation. People will follow you on Twitter. Then you'll just need a reference to this web site in your signature.