Double post because this doesnt directly apply to my response to @Aspie_Gamer but I still want to point it out.
As we've established a longform comic has a significant disadvantage in finding an audience compared to a gag-a-day, primarally due to the fact that they're not as easy to share.
That easy sharing leads to large bursts of new, but uncommited readers. (I've read GamerCat but I dont READ gamercat.) This means that a gag-a-day can generate a lot of ad-revenue over a short amount of time, but it does so inconsistently. The best most popular most successful gag-a-days are the ones that are the easiest to share, they do this by being simple to understand, timley, useful, and sometimes profound. Basically a successful gag-a-day operates in the same way a successful journalist does. Just look at Penny Arcade.
Longforms on the otherhand, are great at building a dedicated readership, but it's just very slow about it. It takes awhile for a good story to pick up steam, but, once you have someone hooked they're most likely with you for the rest of the ride. That consistent readership = consistent add revenue.
On top of this, as your longform goes on you'll have a large collection of pages, every new reader will go through these pages. Which means every new reader is 1 view PER UPDATE. That's a lot of add-revenue down the line if you can keep them invested in your story. Gag-a-days Do not have this advantage. In a gag-a-day, very few readers will go back to your very first comic and read your entire catalogue. If you're lucky they might read the last couple of gags you did. With a long form, if you keep your audience invested, you garuntee that new readers will go back and read the rest of your comic.
Also, with your longform not only will your readers go back and read through the entire story if they're invested, they'll also become more of a fan the more invested they become. This means at the very least you can rely on them to help spread the word of your comic, or even support you in other ways. When was the last time you saw fan-art for a Gag-a-Day? My point exactly.
TLDR: Longforms are much more consistent and reliable for monetary support & building an audience OVER TIME, SLOWLY. whereas gag-a-days can get lots of attention very quickly, BUT IN SHORT BURTS. It's like building a legacy vs having 15 minutes of fame.