Yes you were lucky, very lucky. It's similar to Hi Lo game as soon as you pay for tickets. You bet around 0.03 btc to buy tickets, with a 4% winning chance. Same odds with dice game would have rewarded you far less however, around 0.7 btc.

It's luck, and I wouldn't put money in there. For example to get a 50% winning chance you have to buy around 345 millions tickets (346M minus the 1M you already have bought) at a cost of 690M satoshi (=6.9 BTC), you are clearly not the winner here, even if you have the chance to get first prize.