How do I use the mesh I downloaded from google sketchup as objects on unity

I brought the files (Which i made sure were corect format and etc) into the assets folder (I just did what it shows in the video)and when i went on unity it wouldnt let me use or place the object into my scene. Now on the video he was able to drag the new object from the projects menue into the scene and the game already knew it was mesh. This didnt work for me, but he did use a diferent program than google sketchup so do i have to use that program?