The $100 worth of trades can be done through buy or sell transactions, or a combination of both. You can fund your account with dollars via interac e-transfer, online bill payment, or bank wire transfer, to buy cryptocurrency with dollars. For a sell transaction, you can fund your Netcoins account with cryptocurrency and then sell it on your account. A total of $100 in trades, either buys or sells, or a combination of both, is required in order to receive the referral bonus.
Purchasing cryptocurrency via credit card does not count towards the $100 worth of trading volume on Netcoins.