Any friend of yours is a friend of ours
There's no limit on the number of people you share your link with, as long as their property is brand new to Bulb. And if you know a business who could benefit from cheaper, greener energy, you can refer them, too.
It takes around 3 weeks for a switch to go through. You can keep track of who you've referred (and the money you've earned) in your Bulb account.