Oftenly I use my old piles of altcoins for gambling, due to their value drop in recent months. Most of them were supposed to be successful projects, but majority of them turned out to be overhyped and right now their value is decreasing, so I don't regret using them for online gambling. Yas, sometimes its difficult to find a platform where you can use your altcoins, because majority of online casinos are favouring btc and most popular altcoins. The other difficulty is to find well secured platform, like for example. my favorite one right now is CryptoGamble, mostly because of their high-standard security.