This one is different as it continues the story as opposed to the previous one which was trying to play catch up with stories a year or so behind where the show was at. I can see why this one would be more successful. Plus, not helping matters was people asking the question: why pay for a comic when you can watch the show for free?
The last one lasted two years. All things considered, that isn't that bad.
I don't think you understand. They are doing the comic clearly in hopes that people who watched the Smallville show will hop over and buy the comic. But given how the Smallville comic failed, I think it's given that the overlap between people who are fans and watch the television show and people who are fans and will buy a Smallville comic are minimal.