This question is a bit strange IMO. It's good to have your website -or in this case a proxy- in your signature, but where it will bring in traffic. Having your proxy in the signature on a myspace students forum will bring in much traffic, having it on a forum about France will bring in very little to no traffic.
On this forum it might bring in a few visitors from other owners, to check the layout of the proxy and maybe get some ideas for their own proxies. But I don't think a lot of NetBuilder visitors will be returning visitors