A Menlo Park start-up AdMob focused on mobile phone advertising has raised an undisclosed round of venture capital from Sequoia

The company’s press release yesterday said its global online mobile ad network serves more than 250 million page views per month.

The company was formed earlier this year. AdMob CEO Omar Hamoui also announced that the company has added two investors to its board of directors — Jim Goetz of Sequoia Capital, and Maynard Webb, prominent Silicon Valley investor and former COO of eBay.

The company said eBay Wireless and Nokia are participating in the AdMob network. Bonfire Media, operator of eBay Wireless, began using the AdMob marketplace to promote its mobile applications earlier this year, the company said, but there was no word on how much AdMob is getting for its service.

AdMobs said it is extending a $20 free advertising promotion it launched last week — as a way of getting advertisers started on the network.