Depends on what stage you are at and what type of site you are hosting. You get the advantage of being able to have unlimited hardware space and not worrying about paying a premium for electric to the colo which, in many cases if you aren't serving up video could be a trade off worth making. You also get the hardware physically where you are which can be a benefit. It may not be the desired option the majority of the time but it belongs on the list as an option.