How to target keywords

My site is about funny videos ..i just hardly make anything with that keyword

i get around 50 clicks daily and wont even make 2-3$ from it for 50 clicks and all are US clicks

i want to know how can i see other ads then funny stuff ..may be ads related to credit cards..
YPN provides targetting ..but google doesnt ..any other way for google?

One more Question

If i add something related to credit cards on my site and make it invisible to members(making back ground color and font color same)
Is it Illegal ?? will i be banned from adsense if i do that ??

Thanks in advance

 

Here you go:
https://www.google.com/support/adsense/bin/answer.py?answer=23168

Yes, invisible text violates TOS and can get you banned:

Webmaster Guidelines
In addition to the standards above, AdSense participants are required to adhere to the webmaster guidelines posted at http://www.google.com/webmasters/guidelines.html. Some relevant items from the guidelines are included below for your reference:

Do not load pages with irrelevant or excessive key words.
Do not employ cloaking or sneaky redirects.
Do not create multiple pages, subdomains, or domains with substantially duplicate content.
Avoid hidden text or hidden links.

 

Thanks for your reply Tyler..So any way out for me

 

Start a new site about credit cards

 

Google only advise to avoid hidden text.

 

But it's not worth risking your your SERPs or AdSense account trying to fool Google (especially after you've posted your question in a public forum).