You literally said it's just a guess. It's not. It's a scientific method of estimation which has known expectations of accuracy, and when done right, has a trac

You literally said it's just a guess. It's not. It's a scientific method of estimation which has known expectations of accuracy, and when done right, has a track-record of being able to provide reasonable approximations. Saying it's 'just a guess' implies something very different for which you are rightly downvoted. Second, explaining the basics of random sampling by saying what applies to you, did not happen to apply to your friends/family, implies you have no understanding of the concept of random sampling either. There is absolutely no requirement for your situation to be the same as your friends/family to make this method useful, but by posting it as an argument, you imply that this does matter. For this, your post is also rightly downvoted. As for 'static data', it's a sample to provide insight in a snapshot in time. It doesn't claim to be anything but static. It does exactly what it sets out to do.