[srg0]

> Maybe losing 100k users a day doesn't matter much to yahoo.

1. Not all of them will be lost.

2. 100k/day is probably a lot for Yahoo.

Given camera use statistics, https://www.flickr.com/cameras, we may take the most used breands and count their daily users.

Daily Canon users (brand #1): 41621. Daily Apple users (brand #2): 38002. Daily Nikon users (brand #3): 28667. Daily Samsung users (brand #4): 5007. Daily Sony users (brand #5): 9160.

Thus there are 130k daily users of the top 5 brands.

If we go one for the long tail of the less popular brands, we will probably double the estimate. So it gives us 200-300k daily users contributing images. Losing 100k of them is a lot. But are Facebook users uploading images to Flickr? Are they active commenters? Are they active at all?

[srg0]

Assuming that user contrbutors, commenters and silent visitors ratios are typical 1:9:90, we may guesstimate 2M daily commenters and 20-30M daily visitors.

I suppose that most Facebook users on Flickr contribute few images and logged in with Facebook to leave an occasional comment or two. So this will likerly affect only 5% of commenters.

[danudey]

Your numbers assume that there is no overlap between those groups. It's entirely possible for someone to be both a Daily Apple User and a Daily Canon User (e.g. a professional photographer with an iPhone).