I used an iPhone 4 to shoot this page's previous banner image of a utility pole peppered with staples. With iPhone photos weighing in at a measly 5mb, you might think it'd be a stretch to use them for full-page banners. Especially since the super-horizontal crop required zooming in on just a sliver of the original photo.
In this case, however, it works fine. Here's why.
For one thing, it's a relatively high-contrast scene. Leaving it that way, by skipping a lot of Develop mode work, immediately tells the viewer that this is not a traditional portrait or landscape shot packed with tonal detail. I also converted it to black and white, using a Lightroom preset. Together, the changes serve to shift the photo to an illustration, which our eyes don't expect to include realistic details.
The final step of adding type—by choosing Photo > Edit in > Edit in Photoshop—completes the transformation. The take-away: Used in the right circumstance, small-file photos can punch well above their official weight.