One thing I increasingly noticed with everything I designed was that my choice of font changes how I feel about whatever message is passed across with said design.
It's kind of how color changes how you come across to your prospects as a business (something I'd love to talk about some-time), your choice of fonts can very much influence how your message is perceived or received.
The fonts ought to match the feeling that comes with whatever product, service or scam you're selling.
Let's say that you're selling "luxury" for instance.
That's the center of the brand.
You're not going to do really well using "HEY GOTCHA" font in your designs.
That's the largest font in the image above at the top right corner.
However, the one in the top left could work.
The lesson here is that they are lots of moving parts that ultimately determine how effective an ad design is at achieving the objective.
Every element must work together to sell the message, otherwise it all falls apart.
It either looks very ugly to the eyes or simply fails to convince the prospects.
The brand isn't just the product or service. It's the message, it's the color combinations, it's the fonts and even the little things like chosen icons.