What are the merits of cloning?

It helps feed an enormous amount of people. Virtually every fruit tree producing fruit for supermarkets is a clone.

None for me, I enjoy sexual reproduction.

You can find heaps of info online (databases like pubmed are great) so I wont go into detail but I will give you a few tips to get you started. There are different types of cloning like therapeutic cloning or reproductive cloning. Therapeutic cloning can be used for tissue regeneration of the same genotype for personalised medicine. Look into somatic cell nuclear transfer which is a method of therapeautic cloning. Asexual reproduction is cloning too, and some merits of that is that if an organism is happy in its environment, more organisms will also be happy there, and also, many asexual reproduction techniques require less energy expenditure.