Skeptics of mobile payments need only follow the money to see that not everyone thinks it's all hype. According to PrivCo, which tracks information on privately held companies, the round of venture funding raised by Square last year was one of the top ten largest venture capital funding rounds in 2012.

The Series D round of $225 million, announced in August and closed in September, most notably included $25 million from Starbucks. Other participants included Crunchfund and Citi Ventures. The round was led by Rizvi Traverse Management LLC.

With the Series D funding, Square has raised more than $341 million and is valued at $3.2 billion.

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