There are pros and cons to going with a second (or third or fourth) affiliate network.
It can certainly be an asset to have your affiliate program in more than one network, because while many affiliates join multiple networks - not all of them do so.
If you do have your offer in multiple networks, there can be some pitfalls, such as duplicate tracking.
Also, you have to be sure that you can adequately staff the needs that come with running on more than one affiliate network.
Iíd say that you should try it, so long as youíve tested the tracking and do not have any duplicate tracking issues, as well as enough resources to throw at the added duties.