Apple now has 150 million iCloud users among its device owners, the company announced today on its quarterly earnings conference call.

CFO Peter Oppenheimer said that the company’s cloud syncing and storage service had gained momentum during the last quarter. The new number adds 25 million new users on top of the 125 million iCloud users it named last quarter.

While it has a lot of users, it’s not clear if iCloud is making Apple much money at this point. iCloud is free for the first 5GB of storage, and costs more for extra — $20/year for 10GB, $40/year for 20GB, or $100/year for 50GB. You can use that space  to sync and store music, movies, apps, books, and photos, which you can then access from any of your Apple devices.

iCloud will be deeply built into the latest version of Mac OS X, Mountain Lion, which will be released tomorrow.