Quick Scribbles that crossed my mind. Thought of conveying them to you. Not structured.
As per my old reserach, Frommers did that. It was the only place where US citizens could find reviews of hotels done excellently well.
In one of the books about tripadvisor story, tripadvisor was a small player in reviews segment for a long time as frommers was #1 but recency of reviews gave an excellent quality to review. Also since reviews were written by travellers, so there is always a feeling of connect which is left behind.
Frommers was purchased by Google as well because of the quality of data but later founder purchased it back, because google stopped using it.
Today frommers is at 1.2 M traffic and Tripadvisor is at 160M traffic as per similarweb.
Having said that need and value identified is correct but you will have to figure out how to make this feature into a complete company.
You should meet hotels and travellers both.
Without much connections, we used to sit on airports surveying travelers who used to come/leave from India and abroad and understand how and what of their trip planning. You can do that. It will open your eyes about expectations etc. Tip: a lot of people come to airport early because they don't want to miss their flights. a perfect TG to have a conversation with. Another place identified to meet and learn from hoteliers is Karol Bagh in Delhi if you happen to be in Delhi where hoteliers would talk to entrepreneurs in great details. Just walk in and start talking. Today there are a lot of traveler cafes where you can just sit around and get to talk to travelers.
There are a lot of indian entrepreneurs who are doing reviews, you should meet them up once. They are all very amazing people with brilliant knowledge base and can help you. You can add them on linkedin and if you fail you can get connects from Ashish.
Product-Market Fit importance
Complimentary Feature / Business Battle
Please also map traveler segment, review type with a very good fitment answer. The reason is that there are multiple layers of problems and solutions which can't be discussed on a forum like this. This will enable you to figure out whether your idea is a complimentary feature or a self driving business. In case of complimentary you will need to make it complimentary. A lot of travel startups get killed because they are attacking a feature and confusing it with a business. An extremely well built complimentary value enables you to tap into the market much more effectively sometimes. ex. Booking has 400M traffic and if you can add a way to showcase complimentary review which enables their travelers to convert better, nothing like it. Great opportunity. In India, you will also find that there are certain segments of hotels who barely get reviewed on tripadvisor, so are you building something important here for them. Travelers have different budgets, frequency of travel, planning methodology and you should delve in the numbers to get a good idea.
Few more insights: Please do calculate how do rate of growth of number of properties affect your business and reduces/increases your competitive advantage.
Last thing: First rule for taking advice is that advice can be grossly wrong. Believe in your gut and do something about the insight. Go in field and validate and obsess about your insight. Be ready to fail and fight and die and live a journey !