Growing PPC cost

This year, starting end of last year. PPC (pay per click) cost is going up day by day in all search engines. It is big headache to us too, managing ROI through PPC is highly challenging job now. Need visitors at good conversion rate. but to get volumes and conversion, we have to stay at premium positions on all search engines, Google, MSN, Yahoo mainly. But to be there we have to spend more than $ 10 per some good keywords, but it may not maintain healthy ROI. This is current issue most of online marketers face now and we have done several strategies to overcome this. adding negative key words was very basic practice we did two years ago and still some best experts talk about it. today i read one article about improving conversion through negative key words on PPC campaigns and was happy, we also smart enough that we practices it at beginning of PPC campaigns

here is the article