You are entering a space with a few VERY big names that people go to without even thinking much about it (Agoda is partnered and integrated across many channels, for example, as well as being highly optimized for Google).

Talking business strategy would be a separate matter, but to answer your question as someone who has traveled EXTENSIVELY and lived in many different countries, the two biggest factors for me is price (many of these large competitors of yours have partnership deals with properties around the world, and so can offer discounts - when I worked in hospitality years ago, there were always locked in discounts for anyone who booked through Orbitz, for example), and thoroughness (searching across as many potential properties as possible).

You also have to consider that Airbnb is a HUGE competitor these days (they like to position themselves as a partner in the hospitality space, but let's face it, speaking for myself, I stopped using hotels since Airbnb came around many years ago).