Is it okay to be a member and never post any books? I've noticed that some people do this. Do they  just buy credits to get the books wanted but never have to mail any out?

It is technically allowable but goes against the spirit of the site, I think.  However, just because someone does not currently have any books listed doesn't mean they never did.   They may just be out of books to trade.

A lot of people post wishlisted books only so it looks like they never have a shelf. When I post books a good half of them are wishlisted so they never really reach my bookshelf. I volunteer for my FOL so I'm come across tons of wishlisted books but I also keep a decent-sized shelf too.

This is common for a lot of the members that have been around for a while. They don't maintain a shelf anymore and only post WL books and/or buy credits. Some people jus have more control than the rest of us that are buried in books ;P

Keep in mind that there a a number of families with two accounts.  Often the less active spouse only orders books.  The active spouse posts and mails all the famiy's books and then shares the credits with the other account when they need them.  This would be a logical reason for an account to never have posted any books.  Or if a classroom teacher opened an account with a PBS gift certificate and then had parents donate credits along the way.  Heck, anyone who has ever received a gift certificate.

Kerry

I recently donated all 300 books on my shelf and am now rebuilding it.

I know a couple people who just don't have time to mail out books. They buy credits from other members who mail out so many books that they could never spend all their credits.  There are several people on here who have several hundred books posted and earn a lot of credits-so they sell some to help cover postage.

I usually have a small shelf. Most of the books I post are WL or requested right away. The only reason I have books on my shelf now is that I posted some of my TBR while my shelf is on hold.  I have about 50 WL books to read and I just didn't want to get any more WL books for a while.  So I posted some books that have a lot posted on PBS and a couple that I had duplicates of so they can work their way up FIFO.  I usually donate books that don't get ordered after a while.

I don't have anything on my shelf right now because we recently moved and I sold or donated all my availables.  Now I just post whatever I have that I'm done reading and if it doesn't go by my next trip to the used book store I take it along and sell it.  We don't have as much space in the new place and I no longer have room to keep stacks of already read books hanging around.