Eromanga Sensei (TV)

In ep 5 at 20:10 Tomoe's recommendation corner has a book for Sword Art Online. Also audibly recommended are Shakugan no Shana & Toradora.

In ep 11 at 21:24-22:01 the cast of my little sister can't be this cute makes an appearance in Akihabara after purchasing the main character's from this anime's light novel.

In episode 7, at 7:37, you can see an yellow energy drink that is a copy of a Red Bull can

In episode 8 at the scene starting at 06:58, Gokou Ruri/Kuroneko and her little sisters from Oreimo can be seen being interviewed on the TV that Sagiri is watching.

In episode 8 at 18:10 when Yamada Elf says she wants to defeat Dengenki Bunko, we see Shiba Tatsuya from The Irregular at Magic High School, Holo from Spice and Wolf, and Kirito from Sword Art Online. All three of those light novel series are huge sellers published under the Dengenki Bunko imprint. Eromanga-sensei is also published under the Dengenki Bunko imprint.

In episode 8, at about 07:35, we see Sagiri drawing on her graphics tablet. While the name of the software she is using is not revealed, the user interface of the software is that of Clip Studio Paint (http://www.clipstudio.net/en); a drawing application developed by the Japanese company CELSYS. It also happens to be the most widely used software amongst the users of the Pixiv website.

In episode 11, around 21:30, so you can see the character from Oreimo (My Little Sister Can't Be This Cute) make a cameo appearance and comment on the light novel Masamune and Sagiri just released. Both Oreimo and Eromanga Sensei are series created by Tsukasa Fushimi.