Pro covers one site and Business covers five.
Local and staging copies don’t count: addresses like localhost, .local, .test, or ones starting staging. or dev.. Activate your key there as often as you like.
Moving to another site
On the old site, go to Recipes → Pro and click Deactivate on this site. That frees the slot; activate the key on the new site. Can’t reach the old site any more? Ask us and we’ll free it for you.