Complex sentence: Many systems--such as PayPal, WebMoney, Payoneer, cashU, and Hub Culture's Ven--will sell their electronic currency directly to the end user, but other systems only sell through third party digital currency exchangers.
Split into simpler sentences: Many systems--such as PayPal, WebMoney, Payoneer, cashU, and Hub Culture's Ven will sell their electronic currency directly to the end user. Other systems only sell through third party digital currency exchangers.