First off, let me say that I love being a subscriber as it is a great way to not only support your local comic shop and the titles you love, but also allows you to connect with other comic book geeks/fans. Social perks aside, there are also the discounts you can get if you subscribe to enough titles. Currently, I'm at 15% off which definitely helps financially (helps me to spend more, that is) but wonder if that amount will/can go up as my "Master List" now contains 40+ titles (about half are DC) thanks to the New 52 additions.
Also, because the majority of titles are ones you can't have access to ahead of time,there may come a moment when you will stumble upon one that really clicks with you. In other words, taking a chance with a subscription can certainly pay off if you find a series you like and expand your comic repertoire.
Case in point #1: Batman: Arkham City
On the other hand, what if you take a chance on a title and don't like it? And I just don't mean don't like it, maybe you hate it. What do you do? Do you cancel it? Surreptitiously slip the book back onto the shelf but quickly grab another title out of guilt? Buy it but rage about it to the online community/friends later?
Case in point #2: Onslaught Unleashed- I could barely stomach the first issue but trudged through the second one to give it a fair chance.
Also, can you unwillingly of course, "go crazy" with subscriptions and end up eating cheap Ramen for a month or two? I haven't reached this point yet, but could. The requirements of physical storage also potentially apply to the cons but I'd be interested in hearing about cons from those who subscribe digitally.
Any input is appreciated from the DC wiki community.