Choosing between prepaid and postpaid is entirely customer-dependant, the boons and banes maintaining a perfect balance, at least, as far as price is concerned. The rest, I guess, is pure convenience. A prepaid card is like a debit card while a post paid is like a credit card. In a postpaid connection, the lower airtime rates are compensated with monthly bills. Roaming with Airtel, is possible anywhere in the country, and in many other countries, if you have a post paid connection. With an Airtel prepaid connection, you have roaming only in places which have an Airtel network. You can keep track of each and every call that you make using a prepaid connection, and I have heard people complaining of wrong bills with post paid. The most advantageous part of prepaid (the one which I use the most) is the night time charges. 50 paise for 30 seconds (plus the BSNL charges) for incoming/outgoing calls is acceptable any time for me. For the post paid connections, there are a lot of schemes available now for the corporates, which seem attractive. There are a couple of issues which may hinder further drop in charges, whether in post paid or prepaid. One is the lifting of ceiling levels for the charges by the government (the government feels that there is enough competition which ensures that charges don’t sky-rocket). The second is the fact that all the cellular companies are currently suffering huge losses. One thing that the government doesn’t realize is the fact that all rival companies can come together and decide ceiling levels themselves. Postpaid schemes are available where incoming calls from certain numbers are free. This can be used to track people who are always on the move. For Business men, who travel frequently, post paid is always desirable, if you use Airtel, due to the roaming advantage. I was unable to use BPL or Escotel in my home town in Kerala with a prepaid card, while my friend, who has a post paid connection, could do so, during the entire length of our journey from Chennai to Palakkad. It was pretty frustrating for me.