Why not something like Bit.ly Combination of 6 Chars? 57+B Combination is a good number. For a short URL website. For content website, something like Youtube w

Why not something like Bit.ly Combination of 6 Chars? 57+B Combination is a good number. For a short URL website. For content website, something like Youtube which has combination of 11 Chars. It's pretty good. For them but surely will have a problem in future but that might be after 5+ Years. But if they add one more char, it will have more combinations. If this is about URLs and not files. Can any one correct me if I am wrong.