Shoplifters are caught an average of once every 48 times they steal. Even when they are caught, they're only reported to the police 50% of the time.
Only 3% of shoplifters are professionals who steal for profit. The rest are amateurs who steal to cope with social or personal problems, or who like the "high" from getting away with it. Drug addicts that also become habitual shoplifters describe shoplifting as equally addicting as drugs.
This, and more fascinating statistics are from the National Association for Shoplifting Prevention.