"I wonder why doesn't my work get chosen for Collections on Artfire?" Then you could visit the Art Fire Forums
and put your Studio up for a critique from your peers or you could take a look at your Studio and make comparisons with others that do get chosen for Collections. You are missing an big promotional opportunity if your work never gets chosen and so it is worth spending some time trying to pin point the reasons why and then correcting them.
The main reasons I don't choose something is because the picture is either;
a) too dark
b) out of focus
c) light is glaring off the item being photographed and is spoiling the picture; So think about whether the flash was needed or if the artificial lighting is correctly placed.
d)the item being displayed is swamped by its background; the background being either being too dark, too busy/patterned, unattractive ie there is washing in the background or the nicely knitted baby sized cardigan is being photographed laid on a shabby looking carpet
e) the photograph hasn't been displayed the correct way round (yes really! I know of Studios who have their handmade cards 'side' on)
f) If a white sheet has been used as a background but it is very creased looking
g) If there is very little to choose from
h) If a Studio has been left unattended for a week or more (unless stated that the owner is on vacation) because why should I promote their work when they are clearly not interested in it?