Ever since they introduced referral system, I didn't see a reason to renew ''Paid" licence since I need Eset for one PC only and "Trial" licence has full feature set, just a small non-removable annoyance at "Home" section and at the bottom of UI, but it really doesn't matter, and since "Trial" licence can be added to you personal Eset account, you can use it on different device as well in case you format, and it's not tied to the system you were originally installed 30 day trial on, so you can get in total 210 days of free Eset trial for yourself.. or, your friend. When/if licence expires, you can just switch to the new "Trial" (if you have one added to your account), but that'd be funny since it would result in a somewhat "infinite" trialing period.. My guess is that with this referral way, which is pretty clever in my opinion, Eset is trying to fight against Pirates and shared/stolen Eset licences around www, which I highly advice NOT to use, since your machine appears on owners Eset account, can be deactivated at any moment and all the consequences included with that.