Worthless (in my never humble opinion)
The biggest problem with the Internet is finding stuff on it.
Real estate is mostly local i.e. the California market has no relationship to the Florida market and so on.
Most buyers of real estate in a given area either search local sources for information or, more likely, just get in their car and drive around an area they are thinking of moving to. If they see an open house they like they stop and go in.