Nothing to offer them? What about real estate? Besides what treasures can we not yet conceive of? Whether that‘s an element or a species condition hard to replicate.,(reply>), Assuming a civilization is near enough to travel slower than light without dying and earth is a prime candidate for survival conditions, then real-estate would be valuable, perhaps even necessary for survival.  That aside, I've since changed my mind that the probability of intelligent life forming in our galaxy (and not going extinct too early) might be a lot lower than 1/however many planets are able to form life. NASA recently put out, that they think there are ca 300M habitable planets for us to explore in our galaxy... I personally don't think 1/300M is low enough. <br>But anyway, if ETs would ring our doorbell my bet would be, that they would likely be from another galaxy and travel FTL. Then they would not need our real estate of course. And they would also have no reason to destroy us because leaving us alone for too long would not mean risking our tech progress to reach rival status.,(reply>), Real estate?  If they can travel here, they are probably a level II civilization that can create dyson spheres.  They'd have the capability of changing a planet's entire environment and atmosphere to suite them.  Why would they need Earth?,(reply>), Real Estate to them is like cave to us.,(reply>), Don't have any left,China owns at all!,,(reply>), If a alien species has the ability to travel space freely then they could just go to another planet, why bother with humans when it's less work to just go somewhere else<br><br>There is more than 100 billion planets in the milky way alone