That pretty much sums it up, yes.
Being on the first page in the organic listings and in PPC can help in some cases with clickthrough rates. Sometimes people are more inclined to click on organic links when they also see the same site listed in PPC (and vice versa). There's an element of visual reinforcement and confirmation that the listing is legitimate (or at least that the entity has enough money to pay for PPC) that can make people more likely to click.
So PPC and organic listings can help each other attract more interest.
But PPC isn't going to do anything for organic rankings. (For that matter, nor will having good organic rankings get you better positioning for your PPC ads.)
Edited by torka, 01 February 2013 - 10:55 AM.
edited for clarity.