They are both good ways to get the word out but for my vote I will stick with the W3 membership.
First off neither one has a 100% guarantee.
W3 is a one time cost and if you want to continue getting business cards the only monthly cost is shipping which is stoppable at any time but you are still a member of W3.
The coop is not a bad thing but it cost's more money and if you are like me I have to consider the cost's.
So my vote would be W3.
