"Because it makes more money that way" is the short answer. While this explains why they have a free version, it doesn't explain why they don't have a paid ver

"Because it makes more money that way" is the short answer. While this explains why they have a free version, it doesn't explain why they don't have a paid version as well. There are plenty of people who would pay $.99 to remove ads. Piracy is the only explanation for this that comes to mind.