You are right in the sense that you help a guild by going on their raids, however that implies that you stay with that guild over a long period of time and help them progress. This, according to Jade's own statements, did not occur in his case. He guild hopped until he reached a guild at a point in which hopping was no longer useful. Did he contribute to the guilds he helped, yes. However his contributions were negated the moment he left because any gear he may have gotten from them could have went to someone who stayed with the guild.
To address the purpose of this post, I have found that if you are capable farming the Lasanth entrance can yield decent cash. I have also found harthuks in GD to be decent money. The goblins in starfall used to drop decent enough cash for a lower tiered toon as well. Of course, getting a good group in a high cash dropping zone is always preferable and in my opinion more beneficial for you. If you want to stay with people around your gear, cmal progression is decent for that. Sometimes you even get upgrades. If you don't mind getting help from better geared people, then HHK and FR have had some positive results for me.
Note: Lasanth, Harthuks, and Starfall Goblins should be done by no more than 2 chars, otherwise you are wasting potential.
