Photo quality on facebook?

[Tailgunner]

Who has a 72 ppi computer display?

My display resolution is set to 1600 x 1200.
My screen is 18.625" x 11.75"
1600 / 18.625" = 86 ppi (horizontal)
1200 / 11.75" = 102 ppi. (vertical)

Of course, I can change the resolution of my screen to any of several combinations of w x h.

PPI for display on line is meaningless. You can set the ppi to 1 or to 1000 and the photo will stay the same as long as the pixel dimensions stay the same.
Try it!

The reasoning I've heard behind setting it to 72ppi is to discourage people from saving and printing photos found online

This^

My internet image files don't exceed 72ppi and no more than 800-1000k pixel dimension...especially on FB which as part of it's TOS states they have the rights to images posted on their site.

The problem with sharing a photo to facebook linked from your website/flickr/etc is facebook won't show external links to as many people. Facebook's algorithm already sucks enough for organic reach (I'm talking for a photography page, not your personal page) because they are pushing businesses toward paying to promote their posts. I'm a content creator for a few bigger FB pages (basically an admin) and have learned a lot over the last few months about how FB works with business pages. For example, one of those pages has just over 100k likes, but it's not like every post is shown to 100k people. Depending on how much activity a post gets within it's first few minutes, FB's algorithm then decides what % of your audience will organically be shown that post (it will appear right on their FB feed). Posting external links brings that amount way down.

And this^

 

[KmH]

Who has a 72 ppi computer display?

My display resolution is set to 1600 x 1200.
My screen is 18.625" x 11.75"
1600 / 18.625" = 86 ppi (horizontal)
1200 / 11.75" = 102 ppi. (vertical)

Of course, I can change the resolution of my screen to any of several combinations of w x h.

PPI for display on line is meaningless. You can set the ppi to 1 or to 1000 and the photo will stay the same as long as the pixel dimensions stay the same.
Try it!

The reasoning I've heard behind setting it to 72ppi is to discourage people from saving and printing photos found online

All they have to do is change the ppi value before they print.
You discourage people from saving and printing photos found online by reducing the pixel dimensions of the photo.