PPC (pay per click) keywords are ANY keywords that currently appear within any PPC campaign. These campaigns may include but are not limited to:
a. Google Adwords campaigns
b. Overture PPC campaigns
c. Any second tier PPC systems other than Overture and Google.
Within the Theme Zoom proprietary keyword system, the purpose of the PPC category of keywords is to distinguish between keywords that generate effective paid results versus effective natural results. The PPC keyword category exists so that you may distinguish between contextual keywords