If you're talking about mixing different sponsors free sites with sumbitted free sites so you don't end up with something like
http://sponsor1.com
http://sponsor1.com
http://sponsor1.com
http://sponsor2.com
http://sponsor2.com
http://sponsor2.com
http://freesite.com
http://freesite.com
http://freesite.com
That depends on your LL script. I use the add date field to mix that kind of stuff up. My listings are sorted by date, and I can change it to whatever I need to make the sites appear wherever I want.