Internet titan Google, which is on an acquisition spree, has bought digital coupons and incentives platform Zave Networks for an undisclosed amount. Zave Networks is Google's 19th buyout this year so far.

According to an estimate, Google has acquired over 100 firms in the last decade, starting with Deja, a company in the Usenet space that was later integrated with Google Groups.

This roughly translates into the purchase of 10 companies every year, on average, by Google. Last month, the search engine giant said it would buy Motorola Mobility, the mobile phones division of Motorola Inc, for USD 12.5 billion in cash.

Zave Networks, a company founded in 2006, has announced on its homepage that it has been acquired by Google.

"We are delighted to share that Zave Networks has been acquired by Google. When we had the opportunity to join Google, we felt it was the perfect fit for our company and the perfect opportunity to rapidly drive the deployment and use of our platform to the next level," Zave Networks said on its website.

"We're humbled by the unending support our investors, retailers, advertisers and consumers have provided over the past five years and would like to thank each and every one of them. Going forward, we are excited about being part of Google's efforts in this space," it added. The company did not disclose the financial details of the deal.