In my remarketing efforts, one idea I'd like to hammer home is our social proof. We have lots of happy customers, and I think can be a push for someone on the fence and looking at different companies.
We have several internal successful examples from testimonials used in other channels, e.g., direct mail & email. But a banner ad is so freakin' constricted.
I'm thinking best practice is to have a "teaser" or headline from testimonial, and then invite user to read the rest of the story. But I'm not 100% on this yet, as then have to work out creating a landing page for it.
Do you know of any examples you could share? I've Googled around a bit today, and seen some god awful examples, where someone puts the entire testimonial in a 300x250 with small font below the headline, or someone tells me how they made 5 billion dollars in just a day while they slept.