Best Calling Card

Speak to Travel agents, and make the calling card as part of their tour package – and pay them for every sale made. Thats the best route.
Make ur product available in the online booking websites for travel and tourism – and sell it as an addon. (Jus like “do u want french fries to go with it” – u can sell calling card as a top-up buy).
Position ur card as a cheaper alternative to high roaming charges. Visit www.matrix.in – to see his business model.