Well… maybe instead of a slider, which depending on which articles you read do not have high interaction rates … somthing I agree with only from a personal bias since I virtually never bother even looking at sliders…
Consider, a responsive grid instead of their logos instead … I would imagine your featured advertisers would rather not be hidden in the slider.
And maybe on the directory page where you have the newest … maybe links to your featured too would be appropriate.
I working hard to get Connections 8.2 out this weekend. With 8.2 version, I can release the Widget Pack 2.0. YOu could add all your featured entries to a Featured category and show their name and logo. More details here. As you see the new category widget is for, far more flexible.
In additional, if you opt to add your featured advertisers to a category, you could use the new Custom Category Order extension to put that category at the top of your category list in your sidebar. My goal it to get that released this weekend too.
You could also use some CSS to make both the featured entries and the featured category list item to make them “pop” do something to make them stand out a little more. Maybe for the featured category list item in the sidebar, make it the red accent color that is used on your site. For the entries themselves, maybe just a add subtle background color. You could even use CSS to add a “featured” badge.
Well, those are just a few things that jumped to mind … hope that helps give you ideas!