As Microsoft steps up its assault on the search market, Google has launched a new offensive to tackle the Redmond giant on its Outlook turf.

Google has done everything it can in recent months to make it easy for businesses to switch to Google Apps from Microsoft Exchange and Lotus Notes, launching specific tools such as Google Apps Migration for Lotus Notes and Google Apps Sync for Microsoft Outlook.

Now, a new campaign on the Google Apps homepage calls on businesses to "Join the movement. Spread the word. Go Google."

The company claims that over 1.75 million businesses have "gone Google" so far, and the page lists a large number of case studies of customers using Google Apps, which includes Gmail, Calendar, Docs and Talk.

"Want your company to go Google as well? Contact your IT administrator, share this page with your co-workers and the world, and get others to go Google," reads the web page.

A link on the Apps homepage takes interested parties to an email template they can fill in and send to their IT team to encourage them to switch the business to Google Apps, as well as ideas on how to market Google internally.

"Proud to use Apps? Let others know by posting a Gone Google poster at your desk or around the office," it says.

The Go Google campaign closely follows the Micro soft and Yahoo partnership announced at the end of last week, which will see Yahoo search powered by Microsoft's Bing, while Yahoo will use its solid relationship with advertisers to become the salesforce for both companies' search advertisers.