What casinos actually track
Your player card records: average bet × hands per hour × hours played × house edge = theoretical loss (theo). Casinos comp roughly 30% of theo back as rooms, food, free play, and limo service. The other 70% is the casino's expected profit from your visit.
The math
theo = average bet × hands per hour × hours × house edge
comp = theo × 0.30 (industry-typical rate)
$25 average bet × 80 hands/hour × 4 hours × 0.5% BJ edge = $40 theo. Expected comp value: $12. So a 4-hour BJ session earns you about $12 in comps — about a buffet entry, not a free room.
Higher comp rates exist
- Slots: 30-40% comp rate (slot players are the casino's most profitable customers)
- Video poker: 20-25% (because edge is so low, the comp dollars are small)
- Table games: 25-35% (varies by host attentiveness)
- High-limit pit: rates negotiable, sometimes 40%+ for serious action
What comps are actually worth
A $300 'free' room at a casino that costs $90 to operate is comping you $90, not $300. Mentally discount comp face value by 30-50% to get the real economic value to you. The casino is happy because they keep the rest of your $200 theo.