Megabunk is the product of an idea from several years ago. It's only in the last few years since development got underway, that other, similar sites have come to the fore. By that, I mean they are being advertised to the masses. The idea was to create a site that was completely free to use, yet created some sort of revenue stream to pay for itself. The solution was advertising.
Megabunk is basically just a contact site that is geared towards those who wish to rent out accommodation, those looking for accommodation, those seeking global events and entertainment. From the hotel chain right down to the individual that has a spare room to rent out for a week in the summer. From the Olympic games right down to the village summer fete. The site allows you to build and use mailing lists for each profile and also broadcast across all profiles set up on the same email, as well as being part of a global searchable directory.
Megabunk do not handle the booking process and therefore will not charge any fees or commission. That's down to the members to agree that through contact within the site. The advantage of this method is that it's global. Currency is not an issue.
The service is completely free to use. Not just for the Visitor members, but for the Hosts and Event organisers as well. That goes for all types of Hosts and Event organisers. Your profile can be used as a point of contact, or as sort of free searchable listing. So it makes sense to set up a profile for your property etc if you intend to rent it out or for your event so that you can attract more customers.
A final mention to Geonames.org. It's a free geographical database that's constantly being updated, and it's an integral part of Megabunk. If you are building your own search facility then I highly recommend it.