Hosting your landers under a HTTPS protocol (ex: https://mylander.rackspacecdn.com) is 100% secure in hiding your traffic source if your click URL is HTTP (ex: http://voluumtrack.com/click) right? HTTPS will only pass referrer to another HTTPS and not a HTTP.
Don't want the networks/advertisers to know where I'm getting my traffic from
but it will slow down your LP load speed. split test and see
also its a browser standard , say if you receive clicks from not much know browsers which dont follow standards , it can still leak though.
funnelflux ultimate meta refresh is very good for this.