Coptic Binding has been in use for 2000 years, although few samples survive. It is characterised by the sections of the book being sewn together between boards, and with the spine held together entirely by the sewing threads, which are linked by kettle stitches [124792], or chain stitches, or a similar type of thread usage.
In recent years Coptic Binding has gained something of an artisanal cachet. It does have numerous advantages. I list some here, in the order in which I think of them, rather than by importance, some pros and cons.
It is easy to make Coptic bound books. It is mainly easier to sew by this method, than by binding on cords. Even though Egypt was an extremely advanced civilization there are numerous improvements in tools and materials that required early binders to stick to simple stuff.
To many people the exposed threads and lack of leather backing means an unfinished book. If you appreciate that it is still a form of binding you thereby show a knowlegde of craftsmanship and history. Hence my use of "artisan" = handmade = must be good = supporting local craftsfolk = not made in a factory = environmentally friendly = expensive, of course, but "I can afford it".
On a more technical note the sparcity of clutter on the spine does mean that a Coptic bound book can lie open on a flat surface. For some people that is a huge advantage.
For those with neat finers, and adept with a needle, and a modicum of imagination, inventiveness, or research (the WWW has many examples), there are enormous opportunities for decorative stitching (including multi-coloured threads).
Fixing the boards is full of possibilities. I suspect that a real expert will only accept the rather tricky technique of burying them in the edges of the boards. This is quite easy to do with thick wooden boards - as frequently in the past (= must be good)
When opened out between sections there is a small but unusual gap. This worries some people ("it isn't finished...not properly bound...it is falling to bits...it is different=wrong). (Ignorant folk, they are deriding genuine artisan workmanship.)
For some people many of the above items make for attractive sales opportunites. Go for it!
