I was browsing listings and at the end of a listing were the words powered by eBay Turbo Lister (linked to eBay)
I decided to see how many more listing used that phrase, I found 9370 listings!!!
One enterprising seller had changed it to eBid Turbo Lister!! (Which linked to eBid.com).
You need to do an advanced search for Turbo Lister clicking the 'Search Descriptions' button.
I thought eBay links were removed by admin?
Also
There are 110.831 listings with the word eBay in them! (not necessaraliy links)
There are 2,569 listings with the word Amazon in them.
There are 1,431 listings with both eBay and Amazon mentioned. including Amazon.com Return Policy!
A lot of it looks like it's down to copy and paste from the sellers listings on other sites or just a straight import into Ninja Lister with no description editing.
This could have the effect of moving potential buyers to the other listings.
Just did the same search for etsy, there are 149 listings, including direct links to etsy.