Profile images on Facebook are automatically cropped into a 160 pixel square and reduced to a 32 pixel thumbnail that shows up next to your comments. When you create your profile image, use a larger square. Facebook will automatically reduce it to 160 pixels. Leave a bit of a margin, since Facebook snips a few pixels off all the way around.
Most logos are not ideally presented in a square (and worse, a 32 pixel thumbnail) but there are workarounds. For many logos, simply using an initial(s) from the logo in the recognizable branded colors is an excellent alternative (remember, the name of your company is written in large letters on your Facebook page next to your profile picture, so your profile image does not have to be fully legible).
Here’s an example of a horizontal logo we want to set up a Facebook page for, so we’ll need to create a square profile image that looks good at thumbnail size.
The problem with a horizontal logo is that in order to make it fit in a square it has to be reduced. As a thumbnail (the smaller image to the right), it’s impossible to read and starts to lose the branding.
You need a profile image for most social media, and though this post is about Facebook specifically, the same concept applies elsewhere.