for webgains a username and password are required to download the feeds. It's best to add an extra user for this. Follow the link 'Manage Users' under 'Account' in the menu bar. Pick a nice username and password and select the access level 'none ( no login)'
Getting the feed url
do not use the 'get datafeed' from the program information but use the 'data feed url generator' to the bottom'
In the data feed url generator select the format. Preferred format for webgains is xml. The webgains feeds have the categories as a '>' separated list. The xml parser will split these into single feeds, the CSV parser will not.
It is recommended to generate a single feed for each merchant. The feeds will be smaller and there will be more control when tweaking the data (callbacks).
Select type, merchant, add the username and password as set in the preparation step above and your feed is ready.
Copy the URL into the feed-url of new feed configuration in the joomla section, enter a name for the feed ( = merchant ) and click 'Apply' ( in case you picked the CSV format select the correct CSV parser)