You can exchange your verified rewards with pixiv Points or cash. Rewards are calculated monthly and verified on the 15th of the following month.
Exchanging for pixiv Points
The exchange rate is 1 JPY = 1 point. Exchanges can be made from over 1 JPY. There is no handling fee for exchanging rewards, so it's a good deal.
You can make the exchange on the "Get rewards" page.
Exchanging for Cash
Transfers can be made to your bank account for reward balances larger than 500 JPY.
After you have requested a transfer from the "Get rewards" page, the amount will be transferred to your bank account within 5 business days. A transfer handling fee will be deducted.
Learn more about the transfer fee here.