Buying movie tickets online has been slow to take off. “While online sales tripled over the last few years, they comprised just 2 percent to 4 percent of roughly $9 billion in movie-theater ticket revenue last year, or about $300 million. That will probably rise to $400 million this year. Buying [movie] tickets in advance is not something Americans do. It’s an entrenched consumer behavior to not plan that far in advance when you’re thinking about movies.”