The Baby-Sitters Club continues to be a hit for those who grew up on the series as well as for a new generation of fans. Those fans enjoy showing their support for the series in a variety of online tributes. Some of the better sites and tributes are below.
A recent trend in fandom is to write fan fiction about a particular series or movie. The Baby-Sitters Club is a fairly popular fan fiction topic. Much of the known BSC fan-fiction can be found at FanFiction.net
There is also a section dedicated to the series on Archive of Our Own
Many fans at some point or another gave away their books as they got older only to wish to collect them again for nostalgic reasons. Other fans have a lot of books they have no use for anymore. One way for fans to either pare down or build up their collections is through a variety of book-swaps online.
There is a message board that talks about the series from time to time, located here The Baby-Sitters Club Boards