Welcome to Gaia! ::

You ask them nicely, perhaps through one of those lovely guild broadcasts^^.

For instance, the first time we sent a broadcast in our guild, we talked about all the stuff that needed to be covered, then at the end added a (*48 gold to send) note, and let them to know that it costs guild funds to send messages, create new forums, etc. We got about 14000+ in donations the day after...

As for contests, let them know that there's several contests up. Maybe have a lotto where 10 g goes to the host and 50 g goes to the pot with each ticket bought or something. Maybe have an entry fee for other contests, and link them to where they can start a trade with the mule so that the gold can be used.

Hope this helps!

...where and why, exactly, no one really knows...

well what type of guild do you have?

If it's a general guild, post threads about what's happening on gaia or discussion threads about things that happen in life in general.

if it's a relationships guild (like the one I have) it's good to post threads about just that; relationships.

Gaming guilds get pretty good responses when you post about new releases and whatnot....

Try to explore your options.