A question I’m asked frequently is “how many words does an article need to have to be taken seriously by Google?”. There’s no set answer of course, or else everyone would know it. There are surveys of the average length of top-ranking articles, but ‘average’ doesn’t mean best. The real answer of course is: as long as is necessary. Padding out an article with off-topic content isn’t going to score you any sneaky points with Google, which is looking for in-context content. But relevant supporting material will do you no harm at all.
Two articles on this blog (out of over 3000) dominate the search engine traffic it receives. They are 681 words and 550 words in length, but one is nothing more than a list. Trust me, any of us would be happy with pages on our websites that get these visitor numbers. What they have in common is that they answer a question, and appear to do it thoroughly. And that’s what matters.
The question to ask yourself is probably this: “Is carrying on any further going to help the reader, or am I going into areas which might make them switch off?”