I just got an e-mail from Shopathometv, they are leaving befree as of March 10th. This is what they included in their e-mail:

Note: Our standard threshold amount for monthly checks is $25, however we have reduced this to $10 for the transition. Commission balances of less than $10 will not be carried over to the new program.

I have never earned any commission with these, however, I will never sign up with a merchant who will not pay affiliates what they are due.
Anyone who earned less than $10 will never get paid.
How do merchants get away with it?