Same year, same sponsor, different product
The reason this comparison confuses new players: CSGOEmpire and Gamdom look almost identical on the surface. Both launched in 2016 during the first wave of post-CS:GO skin gambling consolidation. Both have sponsored Imperial Esports at various points. Both accept crypto deposits, both run 24/7 chat support, both support skin betting.
The difference is the centre of gravity of each product. CSGOEmpire's centre is a fee-free P2P skin marketplace, tens of thousands of CS2 skins listed, searchable by float value and discount percentage, buyable with coins that live on the platform. The gambling modes (coinflip, roulette, match betting, case battles) sit alongside that marketplace as ways to grow or deplete your skin inventory. The chatrooms in 15 languages and the Discord-like sidebar are there to keep traders and players talking to each other. Every design decision points back to: you're here because of CS2 skins.
Gamdom's centre of gravity is a full crypto casino. Felix launched it as one of the first CS:GO gambling sites in 2016, but it evolved. The product now leads with its own in-house games (Crash, Dice, Roulette, HiLo, the Gamdom originals) plus a deep catalogue of third-party slots, live-dealer tables, and game shows like Monopoly Live. There's a dedicated sportsbook covering football, basketball, UFC, and esports including CS2. CS2 skin betting is a first-class feature of the site, you can stake skins on any of those games, but it's not the reason the site exists. The reason the site exists is to be a broadly-featured crypto casino.
Which means the decision isn't really "which is better", it's "which one's centre of gravity matches yours." If your first thought when you open the site is "I want to find a specific knife skin," Empire. If your first thought is "I want to spin slots or bet a football match and my wallet happens to hold skins," Gamdom.