A case could easily be made that civilizations that advanced wouldn't be aggressive in any way. We really would offer nothing more than raw resources in comparison of tech and like Blueskies said it would probably just make more sense for them to mine an empty planet. That even ignores the fact our world could just be totally toxic to this other species and something like Mars could be what they are actually looking for instead.
I always laugh when I see the 'advanced civilizations wouldn't be that violent' remark.
If you look at Earth's history, the most violent cultures have often been the most advanced, and typically the ones who have brought with them the greatest advances in technology. Let's face facts, war has created more technological advancements than most anything else in human history. Not saying it would be like that for civilizations that may exist on other planets. But from our limited perspective, it is the most logical view point.
I also look at it this way, if an advanced group of beings who weren't violent were travelling throughout the universe, with that level of technology they could observe our planet and come to know how violent humans truly are. They would be more inclined to leave than to try and land here.