Chet wrote in post #17404346
It still boggles the mind that some will take the time to hand write the information in their post as they must still be unaware of the metadata feature.
The (sad) fact is that people do not read what is on the screen, they might see it but they do not read it. I have seen this over and over again.
Would a reminder like EBay has work? You still have 6 blah blah transaction that you have not added feedback to? A POTN reminder of photo's you may have that don't have metadata? A clear all function could be added to reset the count once you've entered the data to those you wish retained in your gallery.
Actually, a couple of days ago I decided to do something like this:
1. ALL images are added metadata automatically. I mean ALL, millions of them. I'll add metadata save to AMASS image crawler and crawl all the images again. Each metadata item is added if found and not previously inserted. When you post a new image, it is crawled after the post is submitted. Usually this is so fast that when you open the editor it is already filled. If the data is saved before you open the editor after posting, the editor link changes to metadata info possibly with an ADD TO GALLERY button as usual.
The ADD TO YOUR GALLERY button will be shown above the image, not over it.
2. On FYEO, when you open "Your Gallery", you'll have
a) a list of photos that have a camera and a lens found, by forum.
You'll get an "add to gallery" button next to the thumb (= the actual image resized).
b) a list of photos which have metadata, but lack either camera or lens or both. These are links to the images.
Of course many won't ever go to FYEO, so there will be some other method of notification for the possible gallery images. One viable option would be to add to the notification popup a "What Else is going on..." footer which tells you
You have 6 new likes | You have 43 photos ready to be picked for your gallery
The whole approach is like "if they do not come to the honey, let's bring the honey to them" 
I appreciate the brain storming here as this is an important topic.
People include images into their posts to get them viewed.
What might not be clear to all yet is how adding image to gallery REALLY gets your post viewed MUCH more, and keep the post "on the radar" even after it has passed from page 1 a long time ago. The main reason for adding photos to gallery is not the shutter speed, it is getting your work viewed a lot more, and remembered/found for a long time.