Mobile service providers charge High rate in Mumbai.

Why Mobile service providers charge High rate in Mumbai as compare to other state ?

all service provider charging high rate in mumbai e.g.

Reliance india mobile schem Rs. 99 Special Tariff Voucher- Unlimited On-Net Plan

In Mumbai - RIM to RIM night calling free (10.00 am to 8.00 am)
In Punjab - RIM to RIM free.

TATA introduce new offer regarding Internet Plug to surf

Plug 2 Surf: Surf Twice as Much Offer

Value 325 - Rs. 325/month 3600 mins (60 hrs) 8 am-12 am: 50p/min
12 am-8 am: 25p/min
ME Jumbo- Rs. 650/month 2GB Rs.2/MB

Offer not available in Mumbai , Maharashtra & Goa

But in Mumbai

Value 325 - Rs. 325/month 1800 mins (30 hrs) 8 am-12 am: 50p/min
12 am-8 am: 25p/min
ME Jumbo - Rs. 650/month 1GB Rs.2/MB

why they are charging high rate in Mumbai?

Yes not only TATA & Reliance all service provider charging High rate in Mumbai. other state SMS rate is less than 0.50paise or free But in Mumbai they are charging RS. 1 or RS. 1.50