What is a bitcoin casino no deposit bonus?

Could you elaborate on the concept of a "Bitcoin casino no deposit bonus"? I'm particularly interested in understanding how this bonus differs from traditional casino bonuses and how it functions within the cryptocurrency ecosystem. I'm also wondering if there are any specific requirements or steps players need to take to claim such a bonus, and if there are any risks or limitations associated with using a Bitcoin casino no deposit bonus. Additionally, I'd like to know if these bonuses are commonly offered by a wide range of Bitcoin casinos or if they're limited to specific platforms.