Would you advertise a squize page here?

Try to contact the owner first if its possible and ask if you can run a test on the site for 2 or 3 days to check the traffic quality.

Focus more on direct banner advertising for better result and lower advertising cost.

I was thinking to build a list using aweber and as soon as they signed to redirect them to the clickbank vendor. Do you think I should skip building the list and link the banner directly to the clickbank vendor?

You better build a list on a specific niche first since you are using paid advertising. This way you can send the visitors more than one offer.

Keep in mind that you have to give the visitors something for free before trying to sell them anything. IMO don't send them directly to the Clickbank product page, leave that to your email series to take care off. Just use a free offer + Thank you page.

I have tried this before and learned a painful lesson that I hope to avert for you.
One of the main items to be sure of is WHERE the traffic is coming from.Traffic can be sent from many different avenues for many different reasons. You have to be sure about how the site is getting it's traffic. IMHO> Ask yourself this question >Would you EVER allow someone to place an ad on your site if you were sending targeted traffic to it that converts?
A true professional would place an add of his own there now wouldn't he!
I have NEVER had luck with your approach.
If you have $150 dollars to spend every month spend it wisely.
Set up a sales funnel and pay for very targeted traffic to be sent to your site by using PPC or PPV traffic where you can set the keywords for the traffic.
Be sure to use buyers keywords for your main bidding and spend the money there is my advice.
buyer keywords like>
best online weight loss program
proven weight loss program
best online diet program
Get the point here.
To your success,
Cragar