If they want people on 4g
A) offer a family data plan.
B) offer something cheaper than $30. Yes I know they just recently started offering a $20 300 MB plan. However it's only good thru the middle of January. What if someone can't upgrade to a 4G smarthphone until after that? Make it permanent.
C) Higher caps. Lower overages. Charging anything over $1 per GB is rape.