Lesser Search Engines & PPC

Is there any sense in buying ad space or doing a PPC campaign with lesser search engines other than the big 5? Most of their rates are half of what Y! and Google charge. Anyone had any luck with this?

 

Best to focus your energies on the bigger channels. There's a steep dropoff in quality once you get past MSN.

 

Ok - thanks.

 

I would Stick With the big three if your advertising but its your money.