both. It more-so depends on if I'm happy with them; but more often then delete them, I'll move them to scraps but that's usually with older work I don't want in my gallery, but I don't want to delete because it was my "good" stuff at some point. I like to be able to show improvement.
Well its a weird way how things go here on deviantart. Sometimes i see really powerful pieces and they hardly receive a lot of views favourites etc. While a lot of the times i see pieces that and will say it nicely makes me scratch my head twice and they get so many views and favourites that it makes me think its a reverse world. Beautiful work gets pushed away by very very poor work and thats something that is sadly happening more and more. So thats why i leave my work were it is in my gallery and dont delete it. Its all personal preferences
Unfortunately, a lot of the deviations in my gallery do not receive a lot of views - unless they are fanart of some sort. So both my original drawings and photos get maybe 2 views every month, and they rarely to never get faved or commented on. Because I personally like them, I keep them in my gallery. I spent my time on them, and I feel proud of my accomplishment; thus I feel like they deserve to stay in my gallery along with my fanarts. The only time that I delete deviations from my gallery is when I feel they do not reflect my skill anymore. I have slowly developed a better art style in traditional, and gained more skill in digital. Some pictures are...well...bad. In this case, I sometimes keep them in my gallery simply because they have a lot of views, comments, and favs. But if the deviation doesn't have a lot of any of those, then I delete it from my gallery. Sometimes I will delete a picture, even though it has plenty of any of those three; but that's usually because the picture is soooo bad, that I refuse to continue housing it in my gallery - despite what the people think of it.
I purge my gallery once or twice a year. There are many images of my own that I enjoy which have no faves but I keep them because they are ones I'm proud of even if no one else likes them. Mainly, I delete images that no longer showcase my growth in photography. Ones that have a bad composition or are blurry and so on. I have sometimes left an image in my gallery based on how many faves it has or how recent the faves were. If the last fave on an image of yours that you enjoy was a year ago or something you can either showcase it on your profile page or delete it. Either way if you delete images from your gallery or not, you'll always have the image on your computer to find and reprocess.
Most of my older pictures only got one or 2 view, no faves. But I think a lot of that is because no one one here knew me then, so no one really looked at them. I am sometimes shocked to see one first pictures on here get fav'ed right out of the clear blue sky.
For now I keep most all of them because I don't have many. But there are some (especially poetry) that I decide are just too awful or I feel uncomfortable about them in some way, and so off with their verby heads! I do delete journals, unless they are linked to important features or I feel are worth keeping. Ditto to polls.
Uhoh, mebbe I shouldn't have told you? Now you'll have more to worry about. If my journals or polls were really something worthwhile I'd leave them there as least for a year, if not the whole time. But many of mine are just silly fluff or something for my friends and I to chat in and pass some hours. Great for the time, but not really something that needs to stay around.