Don't know how many of you out of there have a collection,a lightbox or both;what I wanted to share with you is my experience about mine and the sales.
What I noticed making my own collections and the lightbox is that my pictures have obviously increased their visibility,but not,as you can think,because of the collection in itself,but because someone else noticed its picture shared by me and thought to do the same or someone else just liked it and thought to use for the collection.
If you think of how many more possibilities and visibility you'll have doing or making your own collection and going around some to search for the best pictures,or what you need for your collection...believe me,even the sales will come,maybe not as soon as you'll make the collections or lightboxes,because all the things take time.
All the top pictures in my best sales are in a collection or more and have been shared by one or more other photographers.
It's obvious that you have to share someone else picture because you like it or think it fits with the collection and then hope someone will notice it and does the same,but if you all start with it I'm sure even one of your pictures will be chosen and shared.
One more thing,seeing the question a person asked for: the difference in between the lightboxes and collections.
For what I know the difference is: the collections are a way the photographers can use to share thier and someone else works,the lightboxes should be more for the buyers a way to collect the best and most useful pictures or illustrations they found around the site.
Here is one of my personal collections and another where I share everyone else pictures and mine:
Wish a good holiday and Christmas time to everyone!