justdave - 8:30 pm on Jan 22, 2007 (gmt 0)

Since your site is general, as you say, I would guess you'll need to avoid niche ppc engines. If you want low cost/click with high traffic, you'll have to dig.

To me, Google will be your best option. a combo of Yahoo/MSN may be a good alternative. I don't know how detail-oriented you are with your campaign on Google, but I assume you are at least tracking conversions. If your conversion/conversion rate/cost per conversion are too high, have you performed any strategic optimization?

I don't want to presume too much on your campaign, so I will just leave it at this. In my opinion, many PPC campaigns "fail" in the eye of the advertiser because they are not systematically and continually optimizing their campaigns.