How many licences do I need?

We are an academic institution. We plan to buy a licence for jw 5 but we're a little unsure about how many licences we need.

We will install two instances of the player, that is, two instances of the player swf file. One on our test server, test.xxx.ac.uk and one on our live server xxx.ac.uk. Both are will fall under the same top level domain e.g. xxx.ac.uk.

We will embed the player code on no more than 10 websites, that is to say, no more than 10 domains. However, we will use the viral plugin so it's likely that the code will be embedded in hundreds possibly thousands of domains.

So do we buy a licence according to how many domains we install the player on (player swf file) or the number domains we place the embed code in? And if it's the latter how do we account for viral embedding?

Thanks