(Image from South Park wikia; memed by me.)
If I could offer one piece of advice regarding marketing and publicity to authors and publishing, it would be: THINK LIKE A READER.
I’m not representative of ALL readers, but I wouldn’t be surprised if I have one thing in common with SOME of them: I would not buy an installment of a serial. (“Series” means something else entirely, so yes, I do mean “serial” in this context.) Your definition of the term may vary, but the crux of it seems to be: one full story divided into chunks and sold individually, usually with a one-week gap between each installment.
Some have likened serial fiction to a TV series: consuming one segment a week. But with so much binge-watching/glomming, the analogy doesn’t quite work.
On the other hand, what if it’s a TV series you’re not entirely sold on by premise alone, and still want to give it a chance? Then maybe you would watch it one week at a time. But would you BUY each episode installment, or just put it in your TV’s planner?
So if you’re a new writer of whom no one’s heard, you may want to tempt readers with a lower price and therefore just give them a taste. Fair enough. But even novels have excerpts as free samples, so if you do decide to serialise, I strongly suggest your first installment is free or close to that.
Serialising could give you valuable insight: Will all people who buy the first segment keep buying until their collection is complete? What would be the drop-off between installments? Would they read their pieces immediately, or save them all up to read at the end? Would you price each segment the same, or have a lower price for part one?
And how would you go about crafting a serial? Write it as a complete novel, fully revised and edited, and then split into parts? Or write a part, then publish, then write another part, etc? If you write by the seat of your pants you may rewrite a lot, so in that case I would not recommend serialising. But for plotters who stick to their outlines, you may be more suited to it.
I wouldn’t buy serial installments, but if at the end you bind all of the parts into one edition I’d buy THAT. In other words, I still want a full novel. I just don’t find buying an excerpt worthy.