Due in part to the centralized nature of current IM systems, new users are experiencing great difficulty in acquiring IM identities with which they are happy. Because each network is so congested, most users are not granted their first choice for an instant messaging handle. Instead, they must either invent extremely creative names for themselves, or they must settle for a "mangled" name, such as "robert253".
A decentralized IM network would lend itself naturally to the generation of multiple name spaces, so that most users can assume the names that they prefer.