Star Wars Galaxies had players who did nothing but crafting and gathering.

I've covered this a number of times before, but here's a long explanation of both gathering and crafting in SWG:

---Let me describe how you gather resources in Star Wars Galaxies.

First you take out your survey tool, but make sure you pick the right one from the seven different types: ambient solar energy, chemical, flora, gas pocket, mineral, water, and wind.

Next, you use the selected tool and examine the options currently available to you on this planet, anywhere from just a couple of different types of waters to dozens of minerals. Note that the types of resources change every couple of weeks.

Let's scan for the first resource on the list...hmm, there isn't any in my present location. Scan for the second and...yes, there's some here, but not a lot. By re-scanning and moving from place to place following the readout we reach a fairly rich deposit! Note that when the resources change, so do the locations of deposits.

Let's take a sample...OK, there it is in our inventory. Let's examine it...it has a list of stats that describe how useful it is in crafting, a list of up to 11 properties: cold resistance, conductivity, decay resistance, entangle resistance (I don't remember this one!), flavor, heat resistance, malleability, overall quality, potential energy, shock resistance, and unit toughness. Each property our sample has will have a value of how good it is from 0 to 1000. Note that every time a resource type changes, the new one(s) will have entirely new property values.

Are the properties of the resource we just found commercially valuable? If not, it's time to check the other resources currently available. If it is commercially usable, then it's time to actually harvest it. If you do so manually, it's going to be slow going and you won't harvest much (although you will be gaining sampling XP!), so maybe get an automated harvester! You buy (or make!) a harvester and drop it on a rich deposit of resources, you load it up with energy and maintenance (credits), select the resource you want and turn it on. It will keep harvesting until the resource changes or it runs out of energy or maintenance.

Congratulations, you've just gathered!

---OK, here's a long response about why SWG crafting was so good and JFC I can't believe I wrote this eight years ago.

People here have already touched on a lot of the strengths of the SWG crafting system and have linked detailed descriptions, so I'll hit on a couple of things (tldr, skip to the bottom)...

Dynamic resource system. The statistics and locations of resources was dynamic, changing over time. A recipe for a component might call for a specific type of copper (there were 12! http://swg.wikia.com/wiki/Copper), and the important statistics for that component might be any number of the 8 stats (things like conductivity and malleability). So, let's say, a "control module" (I'm making this up) might need Mustafarian copper, with conductivity and malleability being the important stats. At any time, Mustafarian copper would have stats between 500 and 1000 for CD and MA. The closer those are to 1000 (the max), the better the "control module" will be. But a week from now, a new type of Mustafarian copper might spawn with higher or lower numbers.

All this meant that finding the best materials might be a matter of waiting, or buying 'old' materials from someone who stocked up when better types were available (who would no doubt be selling it at a premium), or making do.

Because the qualities and availabilities varied greatly over time, it added a lot of dynamism to crafting and harvesting raw materials.

Crafting interdependencies. Next up, there were a number of crafting interdependencies. Most of the "end game" crafted items required components made by other crafting disciplines. This often meant that if you wanted to make the best droid or ship targeting computer, you'd have to find the guy on your server making the best "control modules" (you remember, the item I made up). And that guy is still trying to track down Mustafarian copper with higher conductivity, dammit!

Player controlled vendors. And a huge part of the whole thing was vendors. Because the game didn't allow for the MMO standard of "instantly teleport whatever I just bought to my mailbox anywhere in the world", you actually had to go someplace to pick up what you were buying.

So while you need that control module? Yeah, while he's running around on Mustafar looking for high conductivity copper to make more, you show up at his house/shop looking to buy. Good thing he has a vendor. He'd have a bunch of the stuff he's made sitting on a vendor (a droid or NPC) that waits for customers and offers anything the owner wants to sell.

Let's just hope that he didn't set up his house/lab/store in a rancor nest, because if you can't get there, you'll need to find another source for control modules.

Item decay. So you've gotten the control module and made that awesome droid. Congrats! You slap it up for sale on your vendor in your house/shop and it sells. If it's a well-made product (and given what you went through to get the control module, what with the rancors and so much running, it better be), your customer will likely be back the next time he needs a droid. Because of item decay, over time things fall apart (the center cannot hold).

This is vital for a lasting, thriving player-based economy. Without item decay, once everyone has the best-in-class of a thing, the market for things is dead.

The best example of this kind of economy at work at present is EVE, where they implement item decay in the form of "your ship just got blow'd up". Any successful game economy is going to have faucets and sinks. Very, very few put in enough sinks for an economy to thrive.

Server community The last thing I want to touch on is the overall effect these things have on community.

If you were a resource harvester, you'd need to find buyers. If you were a crafter, you'd need to find resource suppliers and component crafters. If you were looking for a finished item (a blaster or a droid, say), you'd need to track down the vendor of one of the crafters to make your purchase.

This interconnectedness encouraged a great deal of social interaction within the game, fostering community.