It's a good general guideline to use specific landing pages- to take the searcher from what they've typed in and seen in your ad to specifically on your page.

UNLESS...

You have onsite functionality that determines in large part where the visitor goes next.

For example, if you have a questionnaire that helps visitors (or sales people) know what they need, you may not be able to get that much info out of the keyword/ad- Your utility will have to be on every landing page, or you'll have to send visitors all to the same page... perhaps populating some of the form automatically.

This could fit some lead generation systems, for example.

Or if you're in an industry that requires image viewing prior to category decisions... maybe new prospects require a bit of education before they know where to go.

Sometimes the wisdom in your particular niche is that people have to try before they buy, or see it before they know what they want... for example, people may want to buy flowers but not know what species they like.

They may want a new casual outfit but not know if they want a blouse or a t-shirt.

You may have to track your visitors' activity to find out- watch paths thru the site- test different landing pages and compare your CR and revenue.

Don't lose sales just because you took a searcher TOO much at their word and only showed them what they initially asked for. (some get around this by having 'related' or 'suggested items')

Brian B. Carter, MS is a San Diego e-business, copywriting, and adwords consultant. He helps businesses make more money, get better ROI and find more customers by identifying the weak links and overlooked opportunities that are keeping them from their greatest success.