There are many trains of thought on this subject.
If you are in a very high touristy area, there are many B&B's and all of them are on these directories then you need to be everywhere they are. Remember a guest planning a trip goes through the planning stages
they won't necessarily book the first place they see, so if they see you over and over (that is good marketing) and more likely to book a room with you. "Name recognition or branding" we'll call it.
On the other hand, there are directories that plain don't send you any business, they can have all the bells and whistles and they just don't work for you in your location, for whatever reason. So for this you really do need to test the waters and see which are the best bang for your marketing buck.
Your own website is paramount.
Your own website will be the #1 reason they find you online and if you don't have a decent website, you will lose the guest to the next one that is decent.
- Large and clear photographs (of everything pertinent to their stay, ie rooms, common areas, breakfast),
- easy to navigate pages with clear concise information (ie prices and how to book a room easy to find).
- If you require a guest to email or call they may not book a room (some will, but some definitely will not).
- If you cancellation policies are too prohibitive, they might not book a room.
- Some thing very easily overlooked: if the tone of your website is not welcoming then they might not book.
There can be other reasons as well....
- you do not list your location or proximity on a map or link to maps so they can find out if you are close to where they want to go.
- you have a silly website with clip art (this puts off B&B guests),
- you do not provide enough information for them to feel safe in their choice of where they put their money for vacation.
- Price point? Is it too high or too low (too low can also be a problem).
Lastly, not all B&B's will attract tons of guests, location location location.
Then lay out lay out lay out (or in other words the setting).
Many of us are not in tourist areas and have to fight tooth and nail to drag guests in any way we can. So we blog, we market specials or packages on state websites, directories, any place we can.
You need something on the hook to get their attention and have them book a room. As my Daddy always says "You can't catch any fish without your line in the water!" So get the line OUT THERE and BAIT IT!
I hope this info helps, I am not trying to be a downer, but sounds like you needed some info (even if you have heard all this before). You would be surprised the number of inns who just don't have the basics on their websites and actually frustrate prospective guests and send them away without ever knowing they had a fish nibbling on the bait and they failed to set the hook!