I’m adding the 2010 manga-adaptation anime into the sample of adaptation effects on their source material. Many, though not all, series show some degree of significant bump. Nitty-gritty data is collected here, and displayed below. An impressive 20 of the 26 series I looked at made the Oricon charts at some point, though one of them (Rainbow) ended before the anime began. One that didn’t, Seikon no Qwaser, is still running at 8 years, 18 volumes (it’s hardly the only series to run that long without charting, I’m just pointing out that manga can run for a long time without seeing the light of day chart-wise).

Note: For High School of the Dead, both volumes 4 and 5 came out well before the anime, and volume 6 came out during its broadcast. The gap in time was so big that they came out before mal tracked numbers for series, only posting top 10 lists. I used the available 2008 manga data to approximate the average value, in volumes, of the #10 slot to get a rough estimate of the threshold. Even holding v4 and v5 to the maximum threshold from those weeks, the 130,000 v6 and 200,000 v7 it puts up post-anime is evidence of a significant bump.

Arakawa Under the Bridge

Bakuman

Giant Killing

Hanamaru Youchien

High School of the Dead

House of Five Leaves

Kaichou wa Maid-sama

Kiss x Sis

Kuragehime

Mitsudomoe

Nurarihyon no Mago

Omamori Himari

Seitokai Yakuindomo

Shiki

Soredemo Machi wa Mawatteiru

Squid Girl

The World God Only Knows

UraBoku

Working

Series that didn’t chart period, thus not having info available to plot (this does not necessarily mean they didn’t get a boost):

B Gata H Kei
Chu-Bra
Dance in the Vampire Bund
Otome Youkai Zakuro
Seikon no Qwaser
Tono to Issho

Comments:

-While not the original source, the Shiki manga was running concurrently with the anime (same principle as Maoyu in 2013).

-Giant Killing plateaued prior to the anime, which makes the prolonged, steady rise in its wake particularly impressive.

-Some series, notably Mitsudomoe, Kiss x Sis, and Kaichou wa Maid-sama, seem to show either blips or brief increases that didn’t sustain themselves over time. I’d be inclined to chalk this up to how people responded to the present state of the manga; anime might get people to start reading it, but the core content has to be what keeps them there. This is the inevitable fate of manga in general, as many things can cause people to fall behind on a series when it starts to span half a decade.