I would assume it is based on sales. They have run productions of additional games based on sales.

I'm sure if people keep buying them, they'll keep producing them.

There is no set number, as it depends directly on sales. They are set up to change over the line very quickly to rerun more of any given title based on sales. Typically Stern Licenses are for 3 years, at any time during those three years they can run as many as they want to meet demand.

When I was there at expo , they had an Avatar just off the line.. so I think how long their liscence is makes a difference, and at this point, most models are "made to order", meaning they have parts, take some orders, fill the line.. Im just guessing of course.. but how do you explain that. The Disney liscences are probably very time specific, i.e. Tron, so getting runs of a title after the liscence runs is not going to happen..