I am using freebitco.in since couple of years and trying to roll almost every day. But never won something big. I spent more than what i earned from free roll or multi. Spent few dollars on jackpot. But either its my luck or i have got bad client seed every time.
Here are my current status just want to share
I have been on Freebitco.in since late 2014 and I have never won anything more than 3000 Satoshi .....so I share your pain. I can tell you this, back then we won 1000 Satoshi per hour... so I saved up most of those Satoshi's and I got a nice piggy bank score out of that, when the price was at it's highest.

(Back then it was "dust" and not worth anything)
What I am trying to say is this..... The long-term hoarding of these "small" Free spins and Roulette Wheel ...will some day, be worth a lot more... so just hoard them until then.
Small drops of water make an ocean
Even I believe in the fact of saving until becomes a worthy amount. Not on freebitco.in but even I have been saving some satoshis.
I was in need of some money and sold it when the price was at $60k. Nobody knew that the price would dump to this range so soon.
I was fortunate to sell those satoshis at a better price. I am still accumulating from whatever source possible.
I am happy that the Wheel of Fortune makes us eligible to win some decent amount of Satoshis. I had recently won 10k Satoshis through the WoF.
As a strategy this is a good one,the only problem for most of us is lacking of patience.We just think that what we get from the free rolls and from WoF are just pennies and we use them for different things,multiply bitcoin,betting and or buying FUN token(this is actually a good thing in long term perspective).If I had kept all of the wins from my free spins and my referrals wins and if I would have withdrawn them at 64.000 dollars for a Bitcoin I would have cash out a substantial amount of money.Anyway is never late to try and apply again this strategy because who knows what happens after 5 years.