I’ve seen research which claims that a typical article getting to the top spot in Google searches is 1500 to 2000 words. That sounds about right to me. So does your 500-word article stand no chance? Would a 5000-word article be better …or a waste of additional effort?
There’s no answer to that, of course. For uncompetitive searches, I’ve seen some really ‘thin’ content rank top of the Google results. There are dozens of articles on this blog which rank top for all sorts of things, and I rarely write more than 500 words, or you wouldn’t have the time to read it. This page is normally a solid number 1 for ‘4-20mA aerospace widgets’ and it’s just 350 words. But there’s no competition, because there’s no such thing as a 4-20mA aerospace widget.
Content writers who know more than me suggest that after a couple of thousand words, returns diminish. Certainly you’d be better off breaking up a 5,000 word piece into two, targeting different important searches. But the key is to see what the competition is, before you even start to tackle a search with a specific article. It may not require a PhD thesis to be better.