Okay well just off the top of my head...
you have a personals section. Why not place advertising in that section for online dating services etc. that are not free.
you have the free content that will draw people, i.e. the free personals, so advertise for other sites that offer personal ads for a fee and offer you a commission on each sale.
now on to your classified section...
Business services - on that page why not include affiliated business services? Things like credit card processing, business card creation, online payment systems etc.
Autos>Cars: include affiliated shops etc. related to cars. Maybe even auto insurance links would be a good idea in this area.
This is just for starters but I think you get my idea here. Just keep going like that for each of your classified sections. I noticed the large space on the right going down the page with only a couple ad banners in it.
Put more targeted advertisers in there but don't over do it. A few select advertisers per page and evenly spaced is enough. Don't want to make your visitors feel like they are being sold to.
I know that may seem like a lot of work to do each page differently but that is the only way to really make money online. There is no easy way out.
I hope some of this helps you out or at least gives you some ideas...
oh add on here, if you are looking for a good source of affiliate programs start with CommissionJunction:
http://www.cj.com/
That was who I started with first and they really make it easy.
