It's not pure marketing, but it's not the revolution some people are selling either 😅. If your fridge is 8 years old and eating up more electricity, it's probably already pretty inefficient, so switching it to an inverter will definitely save you money on your electric bill, especially in hot areas. What you do need to keep in mind is that the savings depend a lot on how much you use the air conditioning and on electricity prices where you live; in some places it pays for itself in 3-4 years, in others it takes longer. My advice is to do the math based on your current consumption (check your electricity bill) and compare specific models before deciding, because it's definitely worth upgrading such an old machine, but it pays to choose carefully.