5) Because I'm not paying for the horrid data limited overpriced 3G plan to use on a format that I can barely read let alone surf on.
1. Battery life, 3G is a huge power hog, according to anandtech, iPhone gets in web browsing 3 hours on 3G, 5 on EDGE and 7 on wifi!
2. Caps, AT&T may give you unlimited data but in most countries you can't get that, in my country Australia 250mb cap for phone data is quiet common.
3. Coverage, now wifi hardly has good coverage, but it can commonly be found in areas 3G drops out, like inside large concrete buildings, ie skyscrappers or malls
4. LAN connection, you have access to your home or office network, which can be good for an app like the remote on iPhone to control iTunes, or accessing an offices internal intranet or email, or use of ssh or vnc clients.
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