Following I will notify SAM BC users about a problem which seems to be known but not solved from Spacial. It's about the "WPAY" issue.
Working with Sam Broadcaster requires (If you require so) to place a "Buying Link" into the "Song Information Editor" of Sam BC which is seen as "Buy CD". But to fill this line with content you have to copy / paste the Link data manually into SAM BC's editors line, view picture below marked in red.
To pretend this manual action after placement into Sam's database it is a good idea to fill that line in your mp3 file BEFORE you copy it into Sam BC music directory. So FIRSTLY you have to fill the ID3 Tag "WPAY" (Jump to Wikipedia for ID3 TAg specification) - the proper location to fill with buying data with an external program like kid3, mp3tag or similar software for editing ID3 tags. [Remark: Originally the WPAY tag refers to 'Payment' according ID3 tag standard]
Now you have filled the WPAY line. But: Once You EDIT information in the Song info editor in SAM BC and click on "Save Tag" you will discover mysteriously things: the link is fully visible in SAM BC's song information editor BUT is NOT more viewable in any of the software for ID3 tag editing. If you ever intend to move this file to another machine: your buying link is away for any ID3 editor.
A closer look with a Hex Editor program showed that the link was indeed visible in the mp3 data but not displayed in ID3 editor. The following picture shows Kid3 editor view with missing WPAY tag information (Although it is present in mp3 file !)