What's the maximum number of links you should include on a single page? 3, 10, 100?
Let's say you want to build a comprehensive list of the UK charities using Twitter, for instance. There are a lot of links and as the list grows, you just might find yourself with more than 100.
What should you do? For some, the answer comes from the question, "What would Google do?"
Google's guidelines state "Keep the links on a given page to a reasonable number (fewer than 100)."
Not a big help since 'reasonable number' means different things to different people and there's a lot of room between link 1 and link 100. Some people almost certainly err on the side of providing fewer, lest Google penalize them for running a link farm.
Fortunately, we have a definitive answer on this topic: Google really doesn't mind.
That's according to a post by Google's Matt Cutts. In it, he explains that Google's guidelines were primarily based on the fact that in the old days, the Google crawler only looked at the first 100K of a page. While user experience is still a good reason to think carefully about how many links you provide on a single page, Google's crawler is smart enough to not penalize a site just because a page has a ton of links.
According to Cutts, "pages with lots of links are not automatically considered spammy by Google." That's good news.
Of course, he does go on to mention that Google might not follow all of those links but because Google is dividing the passed along PageRank by so many links in the first place, that's probably irrelevant.
Nonetheless, it's always nice to have some concrete clarification from Google, despite their simplicity, a lot of myths do get built up around SEO topics like these.
So, if you've been working on a blog post, The Top 100 X, it's officially safe to hit 'publish'. Finally.