NOTE: This is an open question unrelated to guilds specifically in WoW, but any guild from any game.
What attracts you to a guild?
AND
What causes you to stay in the guild?
This might seem like a silly question, but I've recently started a guild and I'm having trouble keeping people in guild, nearly half of my members have left and activity has gone down to 2-3 online daily. I want to know what I can do as a Guild Leader to change this? The guild isn't on Warmane or even on WoW.
One thing to always keep in mind is that almost all players have a pre-existing expectation from a guild - whether it be progression or trolling ridiculousness. Whatever activity you want to promote in a guild, you need to label it according to convention - raiding, pvp, leveling, or social. That's the basic in introducing your guild to the world.
When it comes to attracting players, there are typically two methods: accidental or intentional. For the former, all you need is a cool head and a genuine demeanor (even if you need to be rude) to meet new people and make new friends. Now the second option is something harder and where you need to grind on. Aside from recruitment ads in global, you need to properly scout players. For instance, when you need to recruit PvPers, you can go to Dalaran sewers and network with the duelers there.
To sustain membership, you need a goal - and consistency, feedback, and initiative to undergo changes to back it up. When I'm talking about goals, you don't need to be a business-nerd planning everything ahead. What I'm talking about is something that excites you, and where the members can go on board.
Let's take the basic goal of going pass BQL in ICC. To do that, you better raid ICC 10 and 25 every week and learn all the ins and outs. If your guildies can't make it to ICC due to schedule conflict, do an easier raid with them instead. Consistency is where you keep the activity flowing, and soon enough your members will get invested in whatever you do.
Guild departures are natural. Some guys we forget, others that surprise us. If you care enough to learn why they left, check your guild log. It will show players who joined, got promoted and left. Ask them why; it wouldn't embarrass anyone at all. On my case, I learned many reasons - and a few of them are caused by simple misunderstandings. For instance, there was a member during the earlier days who left because he hated the discussions in gchat. Upon learning this, I enforced the chat policy, and I've never had a problem like that again.
And as we grow old while the content doesn't age, people are bound to get bored. Some stop playing, while others find a way to make the game exciting again. This is where you actually need to lighten up. If endgame raiding is been-there-done-that, explore the game and find a different area to enjoy. My guild used to be pure-leveling. As more and more members reached lvl 80, I decided to focus on endgame content gradually. While the transition meant reducing my membership count, activity has become more active than ever.
Your question isn't silly at all. We need to talk about guild dynamics (not petty dramas) more objectively, in fact, because it's one of the basic things we can help improve the community. Try to digest my interpretation above, and figure out HOW YOU CAN OWN THIS GAME. Because that inner confidence is your ultimate tool in reviving the guild.
One more thing to keep in mind that A GUILD IS MEASURED BY ITS COLLECTIVE EFFORT, NOT THE SCALE OF ITS MEMBERSHIP. Don't buy into the illusion that your guild is already successful just because you have 30 members online. I stress once again to make an effort in getting to know each member. Even just saying "hi, how are you doing?" from time to time.