The World God Only Knows

[Archangel]

What she lacked in musical novelty she made up for in moe and just general cuteness

That was even more adorable than in the manga, i had a kawaiigasm

[Buffalobiian]

What she lacked in musical novelty she made up for in moe and just general cuteness

That was even more adorable than in the manga, i had a kawaiigasm

I don't quite get her appeal.

Elsie just keeps stealing the show for me. Maybe it's something to do with Kanon's attention-hogging, broken mentality. Even if it's different, the whole "You Must Recognise Me!" attitude ticks me off the same way it does when a rich girl (with followers A and B) says it.

[Ryllharu]

She generally doesn't do that much for me to be honest, but for some reason I like her more than anyone so far aside from Ayumi.

Maybe it's something to do with Kanon's attention-hogging, broken mentality. Even if it's different, the whole "You Must Recognise Me!" attitude ticks me off the same way it does when a rich girl (with followers A and B) says it.

Kanon doesn't have a 'you must recognize me' attitude because she enjoys people seeing her. She's got a complex caused by being ignored most of her life, as shown on the flashback. Its quite different from the point of view of a 'rich girl' as you put it.

I think Zell hits on it, but it seems much deeper than that. She was ignored most of her life, and to garner attention, she put a lot of effort into becoming a popular, likable idol. When someone ignores her, it's like all that effort was for nothing and she's back to being a mousy, invisible girl. She's not demanding attention, she's throwing herself out there.

The problem Keima caught on while he was playing the galge with the idol in it is that Kanon doesn't act like one (at least from his viewpoint). The game idol was singing for the protagonist/player at the ending, yet Kanon is singing to be noticed. She isn't singing for anyone but herself.

It's kind between what RZ and Bill were stating. All that changed when she started focusing on Keima not knowing who she is. Then, she started singing for him. The strange part is that actually made her problem worse, not better. If Kanon was like the cookie-cutter idol from the game, she'd have gotten better with just that. She became even more obsessed with being noticed, despite already having so much attention.

I think her enthusiasm is genuine, but at the same time her motivation is all wrong. Then she flips again when Keima becomes her confidant. However, she starts obsessing about having all of his attention, but at the same time having no confidence in her own actions.

She craves attention, but doesn't seem to have any focus with what to do with that attention.

tl;dr
Kanon is a confusing character. She seems to be very simple, but the harder you look at her, the more complicated she becomes.