Does your Trip Advisor listing say you are fully booked when you are not?
I knew this was a problem, but I don't think potential guests looking for accommodations realize that if you are not listed with one of the OTA's that Expedia owns, Trip Advisor site will indicate they cannot find rates for your Inn and suggest another that is listed with the conglomerate. If you don't have a Business Listing and/or you're not listed with OTAs, travellers can be misled. Trip Advisor is owned by Expedia who also owns Hotels.com, Veneer and a couple of other big OTA's.
Alongside this are their visit date query boxes to take them away from your Inn. If you enter a date then your Inn will disappear if you are not signed up to an OTA or Trip Connect. I don't think a Business Listing will change this at all other than allow you to give them even more money through Trip Connect.
It didn't use to be like that. They showed your details and allowed people to find you. Now, if you don't have a business listing, your business is quickly swept aside. I am aware of this, and if I search for accommodation and see some lovely reviews, I know to go searching out of Trip Advisor. But the average traveler could well take their word for it that you just don't have any availability. This is a big issue for those of you who do not want a business listing, but I have no solution on how to combat it.
Having a business listing won't make any difference as it just adds a direct link to your website. This does make it easier for people to get to your website, but if they want to know your availability from within Trip Advisor you will disappear once they enter dates.
If you want to show up on date searches then you need either to sign up for Trip Connect, or use an affiliated OTA.
Trip Advisor is evolving into a booking site and a pretty powerful one.