Need Help with Adsense

I am newbie in adsense and i tried once with adsense but the problem that i faced how can i display adsense for more than one time in the same ad size for example

i choose ad layout 728 X 90 Leaderboard and can i display it 2 times under 1 table assumption like this

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- adsense 720 x 90 -
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- adsense 720 x 90 -
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what happen is when i do that it only allow one and even i tried other layout still only appear one time, how can make it appear mulitple times

thank you

 

What appears instead of the second ad, is it just blank or do you see Public Service Ads? Google allows up to 3 ad units on a single page. If you are seeing PSAs than it just means that Google can't find enough ads for 2 or 3 units. If you are seeing just a blank perhps it is an error on your code.

 

Yes, there probably isn't enough ad inventory for the content on your page. try 3 125px square boxes, and you'll probably see all three. Care to share your URL?

 

I use this when displaying more than 1 ads unit on my site

So whenever there not enough ads inventory to display, the space will collapse and there is no blank space there. But most of the page I just display 1 ads unit and one adlinks.

 

Yes, probably google can't find enough ads for your page.

You can place Amazon ad URL as the alternate URL - they do have a leaderboard style ad.