I started using YPN this week and it hasn't performed nearly as well as Adsense has for business and technology niches. Switching from Adsense to YPN was trading hundreds of dollars for dozens. I am going to roll YPN out into my non-business and non-technical sites and pages and maybe ease YPN into some low paying Adsense segments. The reason for the drop was the low clickthrough as the $ per click were good. It may be a low clickthrough because I see Vonage/mortgages on first page load and relavent ads after wards.