Differences between 넣다 and 끼다?

[SiEd]

Here's something that's been puzzling me for awhile - what do speakers think the differences are between the "put-on/in-something" verbs 넣다 and 끼다? I've read a couple of studies about these two verbs in particular, and yet I still hear of native Korean speakers (and linguists) who dispute the claims made between these two verbs.