iMessage is an instant messenger service for iOS 5. Via iMessage you can send texts, photos, videos, locations, and contact information using Wi-Fi or 3G. If you are an iPhone or iPad Wi-Fi + 3G user, you may wonder if you use iMessage through a 3G connection; are you consuming data from your data plan?
The answer is yes. The idea was to save users money by turning their text messages into data usage. Interestingly, many users’ data plans include unlimited texting, but not unlimited data. However, if you are only sending texts (not photos and videos) through iMessage, not very much data will be consumed; probably, you’d not even notice.