Ethcombo.com in my opinion is 100% a scam and here is why. Three weeks ago i started using it with my initial first 50 free spins, and won approx $10 and id say i won at least 15 times out of that 50 but pretty sure more. only ever won the lowest reward of (0.00015499) used to get the treasure chest game a few times a day at least but the closer i got to my withdrawal limit, the less wins and less bonus games. never once won the daily bonus for even a few free spins.
Now id say i have rolled about 25,000 spins minimum. I have my main PC which is very decent and has mined me over a thousand spins per day, and i also have 2 old beat up laptops and another not as good desktop mining for me as well all setup to my same ETH address i use on ethcombo.com.that past 6,000 spins have not granted me a single win of any kind. i been stuck at 97% withdrawal limit for 5 days now.
Like i said, you can win like crazy in the beginning, but it slowly gets harder and harder to hit that limit and you will halt completely just before reaching 0.15 ETH.
Notice too a few things, the domain name expires on October 2018, it doesn't plan on being around long. also they have a FAQ's page.... how do i ask a question? there is no link anywhere on the website.The about page says "Read our Blog, check our FAQ or contact our support and we will be glad to help if you have more questions!" with no way to contact support.
So i mined for over 3 weeks, with 4 computers, 24/7 and its turned out to be nothing but a SCAM. Luckily no money is lost other than the added electricity cost which isn't much, but whats more is my time which to me is more valuable.
Don't waste your time and resources on this garbage website.