1)if i have a landing page that is a part of a huge website..does the google bot go thru the entire web site to determine keyword-lp relevancy, etc..or is it just the page pointed at?
2)secondly, what are micro-sites and how are they useful?
what is a better option..to have a micro-site or a page from a huge web site as a landing page?
The question mite sound silly, I know..but I just have to clear some things out in my head and adwords help isn't really proving to be "helpful" on this one! ;)
does the google bot go thru the entire web site to determine keyword-lp relevancy
Most focus is on the landing page itself, but I think some of the links from that page itself may be checked. It won't spider the whole site for adwords quality checks.
micro-sites
I think micro-sites is one of those phrases with more than one definition. However, for Adwords you could create a standalone site in order to better meet your visitor's needs once they arrive, or to allow for testing of performance of different designs etc. The intention would be to create a site more likely to result in conversions, by avoiding dilution that could occur on a landing page that's part of a much wider site. A guess it's a matter of audience/individual preference/testing as to whether this is useful in your case.
There is also some weight placed on the overall topic of the website and how it relates to the keywords in the ad group. When you first create an ad in Google and supply it with a landing page URL for the first time, you'll notice that Adwords will (in most cases) give you a series of keywords that it deems appropriate for your entire domain. If I'm building a campaign from scratch for a new domain, I usually like to use these keywords as starting points as Google obviously already finds my website relevant for these keywords.
There is a theory that smaller sites with tighter focus (GreenWidgets.com) will perform better for keywords surrounding just "green widgets" than a larger site dedicated to the broader focus (Widgets.com). This is with regards to quality score & the landing page relevancy factors, etc. I think that smaller players can use this model to outperform larger sites in some cases but it's sometimes difficult to scale. This might be part of the mentality of somebody building microsites for Adwords.
