As of 2015, you can earn free AMC movie tickets by signing up for the AMC Stubs loyalty program. Although the programs requires a nominal fee of around $9 per year, it allows you to earn a $10 reward for every $100 spent at AMC Theatres through ticketing or concessions.
The AMC Stubs program also includes other member benefits, such as free size upgrades on soda and popcorn. AMC waives online ticketing fees for program members.
Although AMC Theatres does not normally offer other free ticket promotions, you can see current deals and promotions offered by the company by viewing the AMC Promotions section at AMCTheatres.com.