You earn per minute using the Browse feature, and you can track your progress by looking at the round earning indicator at the bottom right of the web browser.
It will count down the minute and then show you how many points you earned in that minute, the total points earned on that day, and your daily limit.
You can earn up to 250 points per day in Browse, so once you've reached that limit, you can still use the feature, but you won't be rewarded for it.