According to a recent research by Ovum, "LTE provides operators with the opportunity to experiment with new and innovative pricing models, which allows them to find the best way of deriving revenues from the premium service .. However, most operators have not grasped this opportunity. Instead, LTE tariffs in the regions Ovum analysed are dominated by unlimited offerings and large data buckets, which can be problematic.”
See "Lack of innovation in LTE pricing models, report finds" - here.
Nicole McCormick (pictured), Ovum senior analyst and author of the report, says: "Operators should not offer unlimited LTE tariffs without some sort of deterrent as they could have an impact on the quality of the service given LTE’s data-intensive nature. However, we note that some leading operators –Verizon Wireless[web site says differently - here], SKTelecom, NTT DoCoMo and LG U+ – have steered clear of unlimited LTE offerings despite offering such packages in the 3G arena"
According to whitepaper by Openet (see "Review of Current LTE Pricing" - here) - ".. The specific usage limits imposed by mobile operators vary dramatically, ranging from 20-30 GB/month in many European markets, to 10GB/month or less in the US and 5GB/month in other markets like Japan"