The bookies know what they're doing. The odds make it extremely difficult to consistently make money. The first bet I made was $550 on Jones to beat Machida in December 2011 and won $100. I almost never bet unless I was completely certain of the outcome and from Dec. 2011 until April of 2014 I had wracked up $3500 in my bodog account (after an initail $750 invenstment).
So I averaged just over $1000/year. I rarely lost, but it's not like I made a fortune either (biggest loss was $300 on Franklin to beat Le). Then I went on a torrid losing streak and I'm currently $300 in the hole lol.
So yeah, I'm confident I'll get back to where I was but it'll take a while. My goal is to get 4-5 grand profit then cash out, but we'll see. It's just a fun way to make some money doing something I love (watching MMA), and if I ever lose that initial $750 I'll quit (and I'm all in this weekend on Lombard lol).