But sometimes the error never appears, and they think you got the message even though nothing came through on your phone.
If you're lucky, your iPhone-using friends will simply get an error when they try to send you an iMessage, and can tap it to re-try sending as text. Unfortunately, iMessage associates itself with your phone number, and when your phone number hops to a device that doesn't support iMessage (for instance, your shiny new Android phone), you suddenly stop receiving your texts. Apple's iMessage is a convenient way to get text messages from users of other Apple products, without actually using text messaging.
