To become an online casino agent for free, start by researching reputable online casinos that offer affiliate programs. Sign up for their affiliate marketing platforms, which typically require no upfront fees. Familiarize yourself with their games, promotions, and target audience to effectively promote their services. Utilize social media, blogs, or websites to share engaging content and attract potential players. Leverage your network and online communities to drive traffic to your affiliate links. As you generate referrals, you can earn commissions without any initial investment.