Oh just so you don't fall victim like others have, make sure you "transfer" your license(s) properly if you reinstall your OS and or remove Blink in the future by following these quick few steps.
1. Go to the "Help" menu at the top of Blink's main window
2. Select "License Management"
3. Select "Transfer License"
4. Respond "Ok" or "Yes" to the prompts about whether or not you want to remove the license completely from your machine.
This should solve any issues you have with reusing that license again on your computers. If you do not follow these steps, there is a good chance that when you go to use a license again, it will either tell you it is invalid, already being used, etc.