In order to effectively compete in the online display-advertising arena with Google (which according to recent stories, advertising is the only priority of the company) and the growing share of Facebook, the mega advertising deal between Microsoft, Yahoo and AOL which first announced in November now goes live.

This new partnership will allow the companies customers a much greater reach for a larger ad inventory “pool” beyond the premium network inventory each company has alone. The basic concept of the trio-agreement is to offer advertisers access to the companies each other’s unsold display-ads inventory to provide more advertising possibilities.

The mega deal suppose to answer Google and Facebook dominance in the online display ad market. According to report of the research firm, eMarketer, in 2012 Facebook will hold 16.8% of the US online display ad revenue market share and Google will hold 16.5%. Both companies predicted to increase their shares by 2014, when Google will take the lead.

The forecast estimates that in 2014 Yahoo (7.5%), Microsoft (4.4%) and AOL (3.7%) will have a combined ad revenue share of 15.6%, which is lower than either Facebook (17.1%) or Google (21.7%) shares alone. With the new deal, the three companies hopes to change this power-balance by attracting more marketers.

Will it be enough to offer real competition? Even though it does look like more attractive and even somewhat alluring for advertisers, eventually what the companies needs to really battle are successful products. After all, it doesn’t really matter how good your commercial is if no one is watching the show.

As for the moment, Google and Facebook own web-products are much better and more popular than all of the web-products of Microsoft, Yahoo and AOL unified (which reflects pretty well on the ad-display market share). So from my point of view, the trio mega deal simply treat the symptom and not the disease.

Here are the partnership companies reactions (which basically say’s the same):

“Starting this week, the Microsoft Media Network, AOL’s Advertising.com and Yahoo! Network Plus are leveraging real-time bidding (RTB) to offer advertising opportunities across all three network’s premium, non-reserved, owned and operated display inventory.” (From Microsoft Advertising Blog)

“The partnership was formed to help streamline the media-buying process by providing more efficient access to premium online ad inventory. The partnership is expected to extend the reach of the companies advertisers, while offering better yields for their publishing partners.” (From Yahoo Advertising Solutions Blog)

“The partnership will fundamentally change the way we buy and sell premium online display inventory and benefits advertisers, agencies and publishers. It was formed to help streamline the media-buying process by providing more efficient access to premium online ad inventory.” (From AOL Blog)