Google, Yahoo, and others are already there, and now Microsoft has decided to follow the leader with the launch of Mobile Display Ads.

On Tuesday Microsoft Announced it had opened the doors for advertisers to display banner ads directly to Windows Live Messenger and Hotmail mobile users.

Microsoft also rolled out its beta for keyword based advertising using Live Search Mobile, to be expanded in the second half of 2008. A select group of “invited advertisers can create keyword campaigns through Microsoft adCenter that target customers on the go. This will be the first time that Microsoft has enabled advertisers to monetize its popular mobile search service.”

Mobile advertising and search is still in its very early stages and, in keeping with tradition, Microsoft has followed behind Google and Yahoo. If they ever hope to boost their market share and better compete with the two leaders, Microsoft should really try launching initiatives like this first rather then constantly playing catch-up.

The service is currently available to advertisers in France, Spain, the UK, and the US. As keeping with the trend of new web developments, Canada is still left out in the cold.