The domain "phon.li" is seven characters. If such a service would to take off, it would become irrelevant after aproximately 630 permutations in which case all

The domain "phon.li" is seven characters. If such a service would to take off, it would become irrelevant after aproximately 630 permutations in which case all the case-insensitive two-letter subdomains would be taken. At best, this shortener would only fulfill it's purpose if the subdomains were case-sensitive, in which case it could only fulfill 1,326 permutations for two-letter subdomains. After two-characters, it's not exactly a shortener since it would be the same length or more characters than the average telephone number.