You have a Real Estate company and you want to put your listings into the MLS and have it display on your website. You don't want to enter it into the MLS and then have to enter in the same information (images, fields, address, everything) in again on your site.
Your MLS is using a piece of Real Estate software developed to make it easy for you to add in your listings and then have those listings display within the MLS, on any site that displays that MLS, until they are removed or sold.
The MLS provides access to this data (called an IDX) so the listing members can display MLS listings on their sites. There are four options that you have to display that data, FTP, iframe, Listings RSS Feed, and RETS.
FTP (File Transfer Protocol):
This is an older solution, and although it is still a viable option it tends to be quite expensive. There is no standard for the data, and changes, which happen often, can make the site obsolete in a very short time. Every time data is updated all the old data is wiped out and all the new data is added. It is very time consuming for the server and the developer. Down times should be expected.
A wrapped or iframe site embeds another website into the pages of your site, kind of like embedding a YouTube video. The video may play on your page, but the video actually resides over at YouTube. The same thing goes with wrapping around your MLS. There is no SEO benefit to wrapping since the content resides on another's website. It only benefits them. There is no way to style the pages either and most IDX iframes are pretty hideous. Forget about being mobile friendly, your users will have to do the "pinch and pan" to find the listings (or visit someone else's site that is easier to view). Also, keep in mind, if a user uses one of the "Request A Showing" forms, the listing agent will be contacted directly, not you.
Listings RSS Feeds
A basic RSS feed is usually available to most brokers and agents belonging to an MLS. The feed itself is generally somewhat simple, consisting of perhaps an image, the property title, and sometimes part of a description. The problem with displaying these feeds on your website is that, once again, the content is housed on someone else's site so your site will lose the benefit of SEO. Another major problem with this approach is that if a visitor clinks on a feed link to read more details, that visitor will be taken off of your site and over to the site where the feed originated. They'd have to hit the back arrow to return to your site (if they don't get busy looking at your competitor's listings).
RETS is an acronym for some complicated words that won't mean much to a realtor. What you need to know about RETS is that it is a data pull directly from the MLS server to your website and will create those listings on your site. They actually create content pages when they come over and are displayed as if they originated from your own site. Think of the MLS's server database as a file cabinet. The pages (content) of a website display whatever is in the file cabinet's folders. A RETS integration pulls all of the data out of the MLS's file cabinets, duplicates it, and places it your file cabinets. The MLS still has their data, and you have an exact copy of it. Your developer can set it up to update the data as often as you wish, so if you want the website to update with the latest data (new listings, sold listings, expired listings, etc) you can set it for, say, every 4 hours and voila it updates every 4 hours! What is really nice is that this data can be styled to layout and look however the website developer wants. Your users will have access to your menu items and any other resources you have on your site with a nice clean professional flow. This also means that if your site visitors fill out a Request Showing form you will receive the email, not the listing agent. You can track your visitor’s site habits with analytic tools and take full advantage of the great SEO benefits of having great content on your site.
Ok, let's talk about the money. Obviously an FTP solution is going to run you the most. You will need a dedicated web professional on hand to keep the site listings up to date. A developer will need to perform the maintenance every time you want to update the data (listings).
If you don't care about SEO, user experience, a professional workflow, and you are on a very limited budget then a wrapped site will give you the best bang for your buck. Just remember to ask yourself why you are getting a website, though. Is it to retain new clients? If yes, then SEO and ease of use should be paramount.
If you want to spend next to no money and don't care if you have site visitors leaving your site as soon as they arrive then a site with RSS feeds of your listings will be the best solution for you. However, be prepared for spending a bit of time on your site updating those feeds, they tend to change.
In my honest opinion, I would highly recommend spending the money and the effort on a site that is actually going to help you to reach your goals. The RETS integration, which while more expensive than an iframed site, will definitely give you the best bang for the buck.
Remember, your website is the hub of your marketing efforts, and having a site that not only helps you to reach your goals, but helps you to organize and set goals, is an invaluable marketing tool!