Are the hottest questions necessarily the right ones to feature? I've seen the following three questions, and one or two more like them, in sidebar ads:
They're not bad questions, but I suspect that their titles won't attract experts to the sites, especially if they pop up out of context. I could be in the minority, but I'm much more likely to ignore the ad and think "what the heck is wrong with this 'Stack Exchange' thing" than click on the link to investigate.
Not all the featured questions are problematic, I liked What is bokeh, really? on Photography. I don't know if it's a good question, but it says "bokeh" so it must be a legit site (see #2 in the advice list). Perhaps the featured questions should be hand-picked from among the hottest questions?