Currently only one company builds, maintains and operates these H2 Stations.
Its the H2 MOBILITY Deutschland GmbH & Co. KG which in turn are six companies (Air Liquide, Daimler, Linde, OMV, Shell and TOTAL).
So its not a law and more market dynamics as it is a monopoly.
Since 18 September last year, the European Central Bank has paid -0.5% on overnight deposits from Eurozone banks. If the bank is charging you -0.4% interest, they’re still doing better than they would be if they weren’t lending the money out.
Banks do all kinds of crazy things to attract customers. Paying 4 euros seems like a very low price for customer acquisition. So really the thought is that you would get this loan from them and be their customer for life.
For some people, there are a lot of better ways to earn 4 euros. The hassle of having to make a monthly payment may not be worth it.
Some thoughts on this
Are you actually going to get it? You probably only get it with a perfect credit rating in which case you are unlikely to actually need it and spend some of your time to earn 4€. This is probably rather meant as an advertisment to get people with a lesser credit rating interested and selling them something that will have positive ...
Don't forget this is a credit just like any other. It will affect your credit rating. This will be good if everything happens just as planned, but bad if problems occur. The credit will show up until paid back, so if you need another credit until then, you might get problems, as you already have one.
Lastly, your rights as a customer may be reduced, e.g. ...
As Pete B. said, it's most likely customer acquisition. However, I'd be wary of two things:
Any hidden costs, e.g. a monthly fee for your monthly payment, variable interest rate, any add-ons like a permanent bank account with that bank (with a monthly fee), etc. With these costs the bank might the winning party here.
Advertisement agreements, e.g. agreeing ...