Elorac:
I personally invest more time, effort and thought in a series as it progresses from one part to another, allowing character and plot development.
It's surely more of a challenge to write a 40,000 word serial than it is to write a 4,000 word story (hey - some folk struggle to write anything over 2,000 words) and the end result is much more of an achievement as it demonstrates skill, technique, imagination, originality, plot devices, characterisation etc. Most importantly, something of more substance can show an author has the capability to sustain a work and maintain their readers interest.
Having said that, I'm sure some people just want a quick fix, and to that intent they may achieve that by reading some of the short story gems in our collection ... or they might get completely hooked and read an entire serial from an author they enjoy.
Personally I think there's way too much emphasis on the number of views and comments. Write something, take a pride in it, and get it out there is my stance. If others enjoy what you've written and tell you so, that's a nice bonus, and it's good to have the feedback/interaction ... but avoiding writing a series just because you think it won't get many comments is a retrograde step.
Another issue emerges from this, and that relates to uncompleted serials. It can be very frustrating to read multi-parts, only to find the work has petered out, leaving the reader unsatisfied and wanting more! Maybe the author has lost interest, written themselves into a hole unable to find the way out, or succumbed to the pressures of life and work and simply haven't got around to finishing it (and I'm guilty of that. One day I WILL finish Linnet and the Raven!). So my advice would be to write your serial and FINISH IT, then submit it.