The higher your ad appears
on the Search Engine results page, the more Impressions and clicks you will be
able to get. You click through rate is also expected to be higher as users are
more likely to click on results at the top. Higher position also means higher
CPC (these 2 metrics have direct connection to each other).
While the goal
might be to drive more traffic and get maximum impression share, it is not
necessarily a good strategy to aim towards top position. In certain cases you
might get more clicks for a given budget on lower positions (which will also be
more relevant) as opposed to the top positions. Ex: your budget is $100, 1st
pos. CPC is $20, 2nd position CPC is $10. This way at position 1 you will get 5
clicks, while position 2 will bring you 10 clicks.