The paid ads and ad words are all labeled "sponsored links" and it's difficult to differentiate between them.
I can always tell the difference.
Premium Sponsorship ads have the words "Sponsored Link" inside the colored box. AdWords have the words "Sponsored Links" above the colored boxes.
Adwords boxes have borders. Premium Sponsorships don't.
Adwords have a PageRank bar. Premium Sponsorships don't.
The #1 Adword is being listed directly below the Premium Sponsorship listing at the top of the page in the same size box/banner. Both of these listings are in colored boxes without borders and with "Sponsored Listing" in the upper right hand corner of the box.