I have a couple questions regarding adwords. I have a small subscription based blog. Basically it is 10$ per year to subscribe. Is there anyway that I can use adwords and then only pay when I get conversions, for example 2$ for every subscription I get from adwords? Also is there a way to use adwords to only advertise on the google SERP page? I only want to advertise on certain serp keywords, not on websites that contain the keyword.
Yes, you can pay only when a person actually subscribes. But You first have to run a regular campaign and pay per click. If you have received 30 conversions in the last 30 days, you use the Conversion Optimizer. There is a help document from google that describes it: http://www.google.com/adwords/conversionoptimizer/pdf/conversion_optimizer_primer.pdf And to only advertise on the google SERP page you have to disable the content network and the Google partners.