You can claim Surfer rewards every day you surf in Hungry For Hits, if you have surfed at least 100, 250, 500, 750 or 1000 pages. You can only claim one prize each day, you will not get all of them. For example, if you surf 100 pages and claim a prize, then come back and surf 500 pages, you will not be able to chose another prize. So claim your reward when you are done surfing, or when you’ve reached the reward level you are satisfied with.
These rewards can not be added to your account later if you have forgotten to claim it one day, so you must actively claim it yourself after surfing to get it. Go to the “Surfer rewards” page under the “Rewards” menu, and select which prize you want to pick in the dropdown menu. Click claim, and it will be automatically and instantly added to your account. This gives you quite a few extra bonus credits, so make it a habit to go claim the reward daily.