[notahacker]

I think it also depends what you're looking for. If you're applying for one of multiple already-existent temporary positions for inexperienced people enthusiastic about learning on the job, appearing to be desperately keen on working for that company specifically probably gives you the edge over many other candidates that might have slightly more impressive universities on their CV. Some fields like marketing might appreciate creative approaches to hacking their recruitment process too, though they'll be more interested in whether your powerpoints are actually good.

If you're a mid-level software engineer trying to get a well-paid job at a company working on completely different technical problems to your skillset and not actively hiring, it's probably wasted effort.

[ghaff]

That's pretty much how I read it as well. Sure, for an internship, lots of enthusiasm probably differentiates you from a form letter and a resume (which, lacking much real experience, doesn't tell you a lot anyway). And, honestly, a followup along the lines of "Thanks. I'm still really interested in your company. Do you have internships or other programs?" would probably have worked at least as well as offering to fetch coffee.

But, as you say, you're probably not going to get an opening created for you unless you have connections and/or a special skillset.