Your goals is really only to keep the honest folks honest. There’s tons of hacked versions of HelpSpot out there and key generators.
I never give those any consideration. You probably could do nothing, just charge what you want and ignore the few people who have the skills and desire to hack it. HelpSpot is encoded with Ioncube which is another option. I do it primarily to avoid modifications by IT which later make the product unable to be properly upgraded, it also helps keep the honest people honest though as I said there’s plenty of ways for them to not be anyway.
For HelpSpot’s market it’s not an issue though, the majority of customers are larger orgs that jump through way more hoops than installing ioncube to install most things. We also have a hosting partner so people who don’t want to bother with anything just use that.
The main thing here is stolen versions generally cost you little or nothing, but supporting those stolen versions cost you a lot. So you want to make sure you have a customer database and probably that it’s hooked in with your help desk app (see what I did here) to make sure you’re not supporting people who are on stolen (or expired) support.