admob details about unique users & possibility of refreshing

In my iphone webapp i use the following admob code for ads:

<script type="text/javascript">
  var admob_vars = 
  {
      pubid: 'abcdexampleid',
      bgcolor: '0F3650',
      text: 'EEEEEE',
      ama: false,
      test: false
   };
  </script> 
  <script type="text/javascript" src="http://mmv.admob.com/static/iphone/iadmob.js"></script> 

While testing the ads, i got logged in to my acco开发者_如何学运维unt and saw in real-time how per-click i was increasing income.

After 2-3 click, it just stayed on the same value. Does this has to do with UU (unique users) requirements?

I ask this because i have a request for diplaying ads on a slideshow picture gallery (slideshow on one url) and what i really want is is it possible to have some sort of "refresh" for the ads on that page, so that they are counted on the admob side?

If it is not, then i don't have to bother with this anymore. If they have some sort of UniqueUsers mechanism implemented on their side, then i think there's nothing more to do for me, but if there is some chance, it would be nice that the page displaying a picture slideshow of 1000pics got distinct ads & clicks.

ps.

If there is big restriction with unique users clicks, can some1 tell me if:

• what is the time-interval admob uses for unique users
• how many clicks a user can make that are positive on the admob before it blocks the same user (unique users)
• how long is a unique users clicks blocked from admob (minutes, hours, exact?)