Everyone's threshhold is different. Be that as it may, I have yet to hear of a person who didn't tire of seeing the same exact information, in both notice AND chat, more than, say, a couple of times per day. When you get tired of it, it becomes spam for you.
I am a member of two help-wanted groups for our club - djs wanted, and "all other staff" wanted. Now granted, they don't place a hard limit on how many notices you can send out - but at the same time, when it's the SAME announcement, sent both by notice and by chat, EVERY SINGLE TIME and roughly ONCE PER HOUR - I don't know of ANYONE who doesn't tire of seeing it.
I was invited to one group, and joined the other on my own - they're sister groups - because we need both DJs and Hosts. I will put out a maximum of one notice - no chat - per day. Sometimes I don't put one out every day. I figure that if someone is truly looking for employment, they'll have their notices turned on, and they'll get it - at least in email.
If someone feels the need to put the exact same announcement in both a notice and IM chat, then I'd say they are fully aware that some have notices turned off. The sad thing is that they don't stop to think of WHY people have notices turned off. Could it be because they are sick and tired of hearing about that particular club/merchandise/event?
I know how to search notices to see if there's anything I want to read. Since I'm not looking FOR employment, I don't really pay attention to the notices that come out of these groups. I'll glance at them, then close them.
Last night was the last straw. I was hearing the same announcements about the same club every single time I turned around - echoed in both notices and chat, from both groups. The only difference between them is one said DJs, the other said other personnel.
When they started up again today, I finally got into chat and asked them to stop spamming. The information was being sent out by one of the OWNERS of the group! I tried to explain in a reasonable fashion why I felt seeing the SAME announcements echoed in both notices AND chat, at least ONCE per hour, was a bit excessive. Someone else chimed in and said she sent out 8 notices last night and got 0 replies. Well, d'oh! Guess she didn't stop to consider that once you've heard it, over and over again, not only don't you wish to work there, you don't even want to step foot in that club. At least that's the way I felt. When they're doubled up in IM chat on top of it, I really REALLY want nothing to do with that club.
People - once or twice a day, in notices, is fine, for a help wanted group. Sending one per hour and echoing the same info in IM chat is NOT going to help you find employees.
It also won't help you sell products, and believe me, I've seen this behavior - and worse - in groups where you can advertise things for sale.
Think about how you feel when you see someone else snowing you under with notices and IM chat for the same thing, over and over, again.
It's a good thing I'm running Firestorm Beta. I can turn off both notices AND chat.