Julian, I am sorry to even be having this conversation with you, because I feel the program is a great one. I am also sorry to inform you, that your wrong. See I have even posted in the past and sent emails to Shane about this very matter. Warning him of this possible issue.
Please let me explain, I at times come across companies and people selling things i am interested in on the web that are advertising lifetime upgrades and such. I try warn them about this marketing ploy and try to help them understand the liability they are causing themselves is extraordinary. When you offer lifetime upgrades and have a free version then it is clearly understood in US law and the US Courts that the free version holds no guarantees or promises. It is also very clear that if you offer a product that lifetime upgrades, ( I recommend companies never do this) then it is very clear, in what that means....... Its that simple. it means " lifetime upgrades". You can try to sell me on whatever new licensing package you want, but when you get in front of a judge or jury, then I think you will understand that all the small print does not matter, because in big bold lettering you used to have and I still have advertising this program as LIFETIME free upgrades.
I try to explain to business owners that by putting that statement on there advertisement opens them up for a tremendous liability, that they could find themselves in a bind in the future, in where they might make a ton of money in the beginning but after all the dust settles and the years roll by their NEW customer base and source in income may dwindle down to nothing after expenses to maintain the " lifetime upgrades". But as long as they have not shut down there current program or filed bankruptcy / solvency then if there are upgrades on this product that they advertised as FREE LIFETIME UPGRADES in the past and its the same program, then they must provide as they advertised, regardless of what new features or new licensing you have come up with.
If Shane had contacted an attorney about this, they would clearly have told him this and explained to him that the only way legally this can be done as u are trying to do , is to shut down tweaking.com and reopened as a new business and change the product name and its base functions around drastically and even then it still could leave him open for liability.
Think about it a minute, in the past, you would see LOTS of companies offering free upgrades for life and now you rarely see that anymore. Most companies offer a yearly subscriptions. Why? Because of this very reason and they finally realized that they could not continue to offer the upgrades free anymore , because there was not enough revenue. Whats sad is, this is a great program and I knew one day that Shane would be facing this situation. But I am sorry to inform you that you can not do what you are doing legally.
Ask your customers to chime in here, what they thought they were buying and then how they felt when they saw this new upgrade that was sold to them years ago... thinking they would not pay anymore to find out they were required to pay $13 to go from 3.9.36 to 4.0? I think you will see what your facing if you do not provide what you promised.
Ill say this, I care about people, and I don't want to see tweaking.com shut down or faced with a lawsuit, so please for your own good, remove the cost and put a donation box in where you are now asking for required payment, ill donate the $12 and I think many will as well. But if you require a payment for something that was clearly LIFETIME FREE upgrades.........then action must be and will be taken. If you don't believe me or think i am just blowing smoke....go talk to a local attorney about what I have said here. 30 days...........