- You can have a “popular” blog (a lot of traffic, a lot of tweets / retweets / shares, etc.), but have very little influence in the sense of being able to change or reinforce opinions or drive your readers to action. A very clear-cut example would be a heavily-promoted splog (spam blog that scrapes content from elsewhere) with no personal connections from the “blogger.” You can get a lot of traffic to the site even if it’s just aggregated material, but the site itself has no influence over readers. At best, the authors of the scraped content have the influence. It’s rarely that clear-cut though. More often you’ll find popular bloggers who just can’t get their audience to take certain actions because the content or style isn’t really designed to do that.

- You can have a relatively unpopular blog in a narrow niche. You won’t have a lot of readers, but if you’re an authority source in that small niche community, you can still have quite a bit of influence in the niche or industry. Consider a very highly specialized medical condition that might affect only 20,000 people worldwide. Even if every single person affected read the blog, it would never be “popular” by today’s standards. But let’s say that blog is run by one of very few doctors specializing in that area. They’re known as the leading expert on the subject. Even though they may never reach an audience of hundred of thousands (or millions) of readers, they can exercise a lot of influence over the smaller community they do reach.

So no, being influential doesn’t lead to popularity. And popularity doesn’t mean you have influence. And that’s not even considering things like degrees of influence. For example, getting people to RT something would considered “influence” by some. If that’s the most you have going for you, I’d call that fairly worthless influence. Anyone can do that by being controversial or sharing links to cutsie crap online. Compare that to someone who can regularly get a large audience engaged in supporting a cause, donating to a certain charity, attending live events, etc., and the level of influence is a bit higher.

Anyone can get people to do something that takes little or no effort if they try (like linking, clicking, or RTing). Not everyone has true influence where they affect people on a deeper level or make a more serious impact on the world, business, or their community.