I hear of a lot of talk of that a ppc campaign with yahoo will improve your SERP results. Is this true?
Unless a PPC campaign is combined with a natural seo effort at the same time over a number of months then i doubt it. In any way i cant see how doing ppc with them would improve serps.
Atleast with Google I have seen that if you have ads running for your site with PPC, your site gets indexed quickly... One of my new sites was quickly indexed once I started few adwords ads...