The Amazon river at its sources is a mere trickle. Six and a half thousand kilometres eastward it has become a mighty force, disgorging up to 300,000 square meters per second of fresh water into the Atlantic Ocean.

A simile that western advertising agencies might do well to ponder as a dribble of global advertising accounts migrate for the first time toward the subcontinent of India.

Whether or not this is the birth of a trend remains to be seen. But in recent months Indian agencies have pitched for - and won - major global accounts in competition with their western rivals.

One such example is Mumbai-headquartered Mudra Group, India's largest indigenous agency which locally incorporates Omnicom's Tribal DDB. Together they made a strategic and creative pitch in London for BT's million-dollar global business-to-business online account - and won against multinational opposition.

Likewise, another Mumbai-based shop, Percept Profile, won a global pitch for Nissan LCV's communication strategy duties, besting the USA's Edelman among others.

But arguably the most significant factor is that in neither case did the client project have a presence in India. The sole local advantages were creative and commercial.

And although one swallow doesn't make a summer, it might just come to pass that within a few years we'll see US and European agency folk emulating the garb of their Silicon Valley cousins.

T-shirts emblazoned with 'My Job Just Got Mumbai-ed'.

Data sourced from The Times of India; additional content by WARC staff