Is the comic even still running? I admit my knowledge of the IP is mostly limited to the movie and animated series, but I got the impression that is was the kind of story that had a logical beginning middle and end. If it's still running after all this time they much have jumped the shark long ago and probably mashed the reset button a few times too.
Honestly though, I think Spawn's moment has passed..
But... but we got two Kick-ass movies! Obviously you don't need to be A list comic property to get a movie!
It's not about popularity so much as relevance. Spawn IMO was at the nadir of a trend in 90's superhero comics (that began with Miller's TDKR) towards ever more darker and exploitative content, mostly just for shock value. I say exploitative, not "adult" or even "mature" because those labels have a habit of being applied to things that are anything but...but I digress. I get the impression comic readers (what few are left) have grown increasingly disinterested in that type of product and I can't see even a new movie re-igniting much interest.
'Kick Ass' was the exception and worked mostly because it chose *not* to be faithful to the tone of the source material and instead take it in a new direction.