yeah, and etsy has also made some changes that make it easier for big factories to make cheap items and sell them on the site, and it's become more like ebay, rather than limiting it to actual handmade items... which kinda sucks :/ the factories keep undercutting artists, listing items for cheaper than artists can afford to sell them at, which means the artists made fewer sales.
SE is a little confusing cause there are a few different pieces. that link is actually to my profile page as a user -- the envies were items that I'd "envied," which is basically their "like" button, and the purchases were things i'd bought. my shop is here affectionatetea.storenvy.com
(with the username at the beginning). i could probably change the "shop" to be something different than my profile url, but then i'd have to update all my links, lmfao. but anyone who signs up/makes a purchase has a profile page! you have to go through a bunch of additional steps to make a shop. by "the people at the bottom" that you're talking about, if you're looking at a product page, I think you're looking at the Similar Products section? so it's other stores offering items for sale that are related to what you're looking at, either through the tags the artists used or the category it's in, or maybe from people who bought similar things. In the box on the right under the description of the shop there's also a section with more from the same store, but it's a little smaller.
Yeah, collections are just. curated lists of stuff, i guess? i would put those together myself. I think they also have a thing now where you can promote other artists? i don't know much about that, i haven't done it. oh, the other thing SE does kinda weird is they have your custom storefront, and then you can opt-in to the Marketplace, and sales thru the marketplace (which is traffic that they've driven to your store) they take 10% on. i just use the custom storefront, since it's mostly people coming from my tumblr/dA and i don't care about them making Marketplace sales for me.
there are also other sites that basically do the same thing? www.bigcartel.com/
is one i've seen, it's the same setup where you create your own merch and they're just a storefront that handles taking payments. i think they only give you the first 5 listings free, but there's no "marketplace" and it seems a little more fine art/indie-friendly? Then there are places like society6 and INPRNT which do all the printing for you, so you make much less on individual orders, but you can offer a wider variety of things since it's all print-on-demand and they handle the printing, shipping, the transaction, buyer complaints, etc.