What an obvious concept.  If intelligent life exists (and it is statistically more than likely), wouldn’t it be obvious that if they know about our existence, they would already be sending us signals?  The purpose being that simply by receiving and responding to said signals, we would be telling them that we have finally developed our technology to a point where communication can be made between our worlds. 

I think that while it is important to for organizations like SETI to be sending out signals, it is equally (if not more important) to be listening.