They also provide payments plans (pay in 3/4 instalments, or over a year or two) which often, but not always, charge exorbitant rates. I've bought stuff split over 3-4 instalments multiple times for free or for a minimal processing fee (like 3 euros to pay 1600 euros in 4 instalments over 4 months). Always for stuff that I can afford outright, but would prefer to split the costs over multiple months.

They probably make their money from the seller who banks on the fact that people would be reassured of being able to afford the high priced item, and thus be making more sells than otherwise.