Hello!
Be aware that 4 Mbit + 4 Mbit/s of guaranteed allocation is great for the pricing of AirVPN. Our competitors offer 0.0 (best effort, no minimum allocation guaranteed). Please consider that if residential ISPs in Europe had all of their customers connected simultaneously and requiring full bandwidth at the same time, the allocation by most of such ISPs (if performed equally for each customer) would be between 0.1 and 10 Mbit/s.
The biggest ISPs in Europe (example: TIM in Italy) have an average per residential customer consumption (fixed lines: in mobility much less) of 190 GB/month, which on average means 0.58 Mbit/s throughout the month. Residential networks are normally designed and sized on the basis of these values with congestion control (traffic shaping) during peak hours or any unexpected event.
Guaranteeing no overselling beyond 4 + 4 Mbit/s was and is even nowadays a significant effort by AirVPN. In practice, as you can see on the "Top User Speed" chart, users can easily beat 500 Mbit/s, there is no congestion. But if all customers connected at the same time (assuming a fair distribution on all servers) then everyone would anyway have 4 Mbit/s (4 + 4 server side).
Kind regards