I'm a diehard subscriber. I love the convenience of getting my comics delivered to my house, and would never, ever consider buying a comic book at a retail shop. There are 3 main reasons I have for this:
1) Gimmicks. I believe that comic book specialty shops have restricted the reach of comics. This, in turn, makes them prone to relying on gimmicks, crossovers, and publicity stunts (or "relaunches") to boost sales every so often, rather than just relying on good writers and excellent art.
2) Price. I currently subscribe to 28 monthly titles, and I pay what averages out to 30% of retail (assuming $2.99 per issue) for my comics, direct from DC and Marvel. (that's 70% off the cover price) Why would I want to spend 3 times as much for my comics? (or have to subscribe to only 1/3 of the titles I get now)
3) Convenience. Without lifting a finger, I get the issues of my favorite comics in my mailbox every month. The mailman is already going by my house every day anyway, so I consider it the environmentally friendly thing to do. No extra wasted gas or time every month.
Now, this brings me to a question. I know there weren't any comic book specialty shops when I was very young. The first of them reared their ugly heads as the 1970's drew to a close, as I recall, and didn't start spawning in most of the cities around me until the early to mid 1980's.
Does anyone know in what year these evil entities managed to surpass the traditional subscription sales of comics? I've always been curious about that.
BTW, the lamest comic I'm subscribing to right now is Aquaman, which has perhaps the worst artwork I have ever seen. The best would be a tossup between Exiles and Green Lantern. (if you don't count the Frew Phantom, which I get by trading with a guy in Australia)