Google, Tsar of the globe's internet search business, is to extend its advertising reach through a significant new venture -- keyword-based advertising via e-mail.

It was reported Friday that Google plans to open up a huge new market for its lucrative 'sponsored links' advertising by welding these links to a new Google-branded email service. This would not only enable the company to tie users even more closely to its search site but also entice customers from rival search engines.

The California-based internet giant has recently made several email-related acquisitions, and is actively exploring ways to serve relevant ads to emails at the moment they are opened, say insiders.

The most likely scenario seems to be a closely-targeted email service free to users in return for completing a personal interest and lifestyle questionnaire. The company recently registered the domain name

Responding by email to questions posed by Reuters, Google's David Krane said: "Google has a number of projects in the works to test monetization in various scenarios. In fact, Google's AdSense contextual ads are already used in a number of e-mail newsletters."

Data sourced from: Reuters News Service; additional content by WARC staff