If you list and relist (or are planning to) hundreds of items or more with eBay, and you don't use Turbo Lister, then at some time you will probably have to change some detail in all of your listings. For example, if your contact details are shown in your item description and they change.
It can be a very time consuming process to make these sort of changes to all of your listings.
I work closely with a business that usually has close to 1,000 listings at any one time, and over the years they have had to make several changes, such as when they changed ABN, eBay user ID, postage costs, their telephone number, and once when their listings contained a violation of eBay rules (a link).
The solution I came up with for them was to put all of their contact details, shipping costs, payment terms, etc into a graphic file (hosted on their own server) and include that in each listing.
When there is a change, we simply change the graphic file and all listings are always up to date.
The other advantage is that they can easily track how many total page views they are getting on eBay through their server statistics, and what the most popular products are.
Depending on how you list and relist, you should consider this if there is the possibility that any of your details may change.