This question is quite a hard one if you look at it. There are various advantages and disadvantages associated with it. Primarily, it is never advisable to marry someone in a hurry and especially someone that you have just met over the internet. Instead, one should try to give it some time to get to know the person as well as possible.
Hence, dating the person for a while would be a good way to figure out whether it would work out or not. Remember, do not marry anyone in hurry because people on the internet usually tend to be quite shady.