Thread: Airtel unlimited calll offer

I received this mail today:

Believe it or not!
Now you can make unlimited calls from your Airtel Fixedline for just Rs.500, at no additional charge in your current billing period. You simply have to talk upto Rs.500/month and then forget about any further charges.
So go ahead, talk worth millions?
Offer Valid on all local & STD calls. The offer is made available exclusively for you. Selection has been done on a random basis. Offer is at the sole discretion of Airtel.

What the hell does it mean

Is the offer valid for A2A calls only?

From what i understand it means all calls(local & std) are free beyond call usage of Rs500 .I haven't confirmed from cc