Facing competition from recently acquired AdMob (Google) and Quattro Wireless (Apple), mobile ad network Mobclix has been steadily working to strengthen its products and offerings. The startup just acquired iPhone app sales analytics software Heartbeat and announced a deal to offer Nielsen’s ad targeting data into its ad exchange to enhance ad targeting. Today, Mobclix is officially launching one of the first SDKs for iPad advertising.

Apple’s new tablet device, which will be delivered to consumers in a few weeks, poses a tremendous opportunity for advertising. The size of the tablet not only allows for larger ad sixes but ads can also be more engaging and media rich, with the possibility of incorporating video and other interactive features. And these means more revenue for advertisers and developers.

Mobclix allows app developers to sign up with their ad inventory and ad networks bid for the spots based on age, gender, location, and other factors. The ads being served change automatically, based on which ad network is bidding the highest to reach the users of that particular app. It also lets advertisers buy across a variety of apps based on demographic, geo-targeting, and behavioral characteristics.

Mobclix ripped its iPhone SDK apart and completely rebuilt a new SDK for the iPad. The startup says that thew new iPad advertising opportunities means higher eCPMs and more options for ad sizes. Currently Mobclix partners Traffic Marketplace and Valueclick are offering the 300×250 ad unit for the iPad. But Mobclix will be launching 468 x 60, 120 x 600, 728 x 90 formats by April.

Of course it should be interesting to see how Apple’s own mobile ad network, Quattro Wireless, will play into the advertising ecosystem on the iPad. While it’s unclear what Apple’s plans are for Quattro, we do know that Apple is bullish on mobile advertising and may be developing its own mobile advertising offerings for developers. And, Quattro Wireless is one of the networks that is included in Mobclix’s exchange.