Why are sim-only deals cheaper than regular mobile contract deals?

First of all, to cut the story short, we remind you once again that a sim-only deal is a package which normally includes minutes, texts and data at a fixed price per month, while a mobile contract as the name suggest, provides you a handset and a deal with a fixed monthly price normally spread into 24 months. So, what it’s cheaper? Sim-Only deals are. And why? Because using a comparison, the amount of money you spend during the 24 months that includes interests, handset and sim deal is way much more comparing the purchase of an handset paid outright and to which you can later add up a sim-only deal to it.