I noticed that for a particular AdGroup one can enter a destination URL for specific keywords in that group AND in the section where you create your Ad text (slogans and calls to action). My question is: why are there two locations for these destination URLs? Which location overrides the other?
The keyword over-rides. It's useful sometimes if you want to send someone to a different product page, when it's something that is in the adgroup for that ad text, but comes in slightly different varieties, for example