Now that we have been traveling for about 4 months, I think we have become pretty savvy at finding accommodations.
When a hotel or hostel registers with a site, they adjust their rates to compensate for any commissions that are charged by the referring website.
Make your decision based on comfort, location, and other amenities that are important to you. After you have made the decision on where you want to stay, just do a quick comparison on a few other sites. I have found the most popular to be Booking.com or Agoda.com. Most all travel sites are now owned by Priceline, but even they will have a different advertised price.
Below, I have taken screenshots of three separate prices for the same room on the same dates. Most of the time, the prices are very close, but I have run into a few differences that are much more significant.
As you can see, there is a difference, and if you are pinching pennies, it could add up to a meal over the length of a stay. Remember that most all sites price match as well, so if you are a member of one and find it for a lower price, just let them know!
If you travel often, pick a pony and stay with it, as you will get perks, secret deals, and deeper discounts. I book 95% of all of our stays through Booking.com and get the best deals I have been able to find. Agoda.com is new and offers rebates after stays, but it also processes its payments in Europe, and foreign transaction fees can add up quickly.
With our Genius status with Booking.com, this room only cost us $21 per night!