Apple?s first social network service, Ping, has reached 1 million users in 48 hours.

Ping was announced last Wednesday at Apple?s special event as part of iTunes latest update 10.0. Ping is a social network based around what music users are buying from the iTunes Store. Much like Facebook users add their friends and comment on their own or others purchases. A custom music chart is built on a users circle of friends.

iTunes is already run by more than 160 million users, so it?s no surprise that they broke the one million mark in 48 hours. Apple have revealed that one third of those that have downloaded iTunes 10.0 have signed up to Ping. Apple?s vice president of Internet Services, Eddy Cue said the following: ?One-third of the people who have downloaded iTunes 10 have joined Ping. As many more people download iTunes 10 in the coming weeks, we expect the Ping community to continue growing.?

Apple is happy with the uptake for Ping, but some are a little surprised that the number isn?t much higher considering how many people use iTunes.