Whilst it is true so many online businesses today are doing a form of the Freemium model there are many others to consider, in varying forms.
For example in the 1990's many computer games were given away free with magazines, but you could only play the first few levels - one had to pay for the game to get the full experience.
This is still digital I guess so perhaps consider some nightclubs. One can enter for free or for a low cost, you experience what is going on, but there will often be a VIP area which will require further payment.
Finally consider the number of free seminars on financial advice, or companies offering to give you your suit measurements for free - they offer a service for nothing but in the expectation that a small number of users will spend more on the full product. This can also be found in professions such as accountancy, law or at a gym class where your first session is free but you have to pay for the further ones (or private ones with a personal trainer Vs bodypump with the masses)