Stage 3 (sell your accommodation on Online Travel Agent (OTA) websites)
You have a business website with a web booking engine, and a separate listing with an online travel agent. Examples include Booking.com, Expedia, Hotels.com, Airbnb and HomeAway.
Are you not using a channel manager? (explained in stage 4) Then you'd need to update your availability and price on your own website and for each online travel agent's site you have a listing on.
If you don't make use of an online travel agent
You may be able to use your own web booking engine to display your prices directly alongside the agent's prices.
If you make use of an online travel agent
Metasearch sites will usually pull your availability and pricing info directly from the agent.
As such, your accommodation will gain greater exposure online. Potential customers will also have more chance of finding you.
read about your business
check availability of your accommodation on the dates they want
book your accommodation
pay for their stay
also check availability, book and pay on the online travel agent's website
The benefit of working with an online travel agent is that you will be discoverable and bookable on both the agent's and metasearch sites.
A metasearch site is a comparison site. Think of Google Hotels, Kayak, Trivago, TripAdvisor, and Skyscanner.
It lets customers compare prices for your accommodation across different websites. This includes the online travel agent's websites and (sometimes) your own website.