Try this link....Well I have 1 classified open and tried to do another. I got a message telling be I had too many open and to close one before opening another. Strange.....
It shows a chart that lists the benefits to each catergory of participation on BYC.... Look at the bottom of the chart and you will see the info about # of ads allowed
https://www.backyardchickens.com/a/byc-memberships-help-support-backyardchickens