The results are different now. A Google search today with the straight quote results in his post showing up with the whole "I'm a Celebrity" phrase bolded. Here's a screenshot:
My first thought was that he'd changed the title of the post, but no. It still has the smart quote in it:
1. <title>I’m a Celebrity 2009: ITV neglects its SEO » Malcolm Coles</title>
It looks like Google is converting the smart quote — the ’ in I’m — into a plain single quote — the ' in I'm — on its end. In fact, if you inspect element and you'll see definitively that the former smart quote is now a plain quote.
Often SEO gurus like to pretend that Google is the only search engine, but it's not. According to the December 2014 comScore numbers Google only had 65% of desktop searches, so we shouldn't forget the other 35%, the biggest chunk of which comes from Bing.
The good news for us here is that Bing is treating smart quotes (almost) the same way… I searched on Bing for the same query and, although they didn't convert the smart quote — see inspect element — the whole "I’m a Celebrity" phrase is bolded as it should be:
Of course, this is all based on speculation. No mention of smart quotes is made in Google's SEO Starter Guide and I haven't been able to find a guideline elsewhere in Google's or Bing's documentation either despite a fair amount of searching. But, my recommendation going forward is going to be to use smart quotes.
My final check was to see what the a few of the big sites out there are doing. The New York Times uses smart quotes pretty much exclusively, it looks like. Smart quotes appear in the title and body of this book review, and even in the meta description (though the HTML entity is used there):
1. <title>David Axelrod’s ‘Believer’ - NYTimes.com</title> 2. <meta itemprop="description" name="description" content="A memoir by David Axelrod, Obama’s strategist and political adviser." /> 3. <p class="story-body-text story-content" data-para-count="559" data-total-count="3180" itemprop="reviewBody">That 2004 Senate race built the foundations of Obama’s presidential run four years later. Axelrod proved to be a superb strategist and message maestro. He was the one who came up with the tag line for Obama’s ads in that race, “Yes We Can!” “I loved the . . . line,” Axelrod writes, “because it gave voters a stake in making change happen. It wasn’t just about him. It was about what we all could do together.” Obama thought it corny, but his wife, Michelle, disagreed; it stayed in and became the rallying cry then and in future campaigns.</p>
The same seems to be true in all other NYTimes.com pieces as well. The Huffington Post, on the other hand, seems to use straight quotes exclusively, as seen in this article:
1. <title>More Evidence That 'Centrist' Solutions Can't Save Us | Richard (RJ) Eskow</title> 2. <meta name="description" content="We have become a profoundly unequal society. Unless we can build momentum for a new political agenda, we'll be divided into a small minority with fabulous wealth and a permanent underclass with few hopes or prospects. Unfortunately, our mainstream p... "/> 3. <p>The "politics of envy" is another favored conservative trope, and it's troubling to see it adopted by Democrats. But it fits with the overall message, as conveyed by the Clinton associates who spoke with Amy Chozick of the <em>Times</em>. Their consensus appears to have become slightly more liberal, but their policy prescriptions still seem to fall far short of what's needed.</p>
Both of those publications, obviously, get tons of traffic and perform well in search. So the fact that one uses smart quotes and the other doesn't leads me to believe that maybe the question isn't even that important. Reading the beginning of Google's latest post on the Webmaster Central Blog helped confirm that suspicion. The post wasn't about quotes, but it included three of them in the first two paragraphs, and there wasn't any consistency in how they were displayed. One was smart, two were straight:
1. <p>Locale-adaptive pages change their content to reflect the user's language or perceived geographic location. Since, by default, Googlebot requests pages without setting an Accept-Language HTTP request header and uses IP addresses that appear to be located in the USA, not all content variants of locale-adaptive pages may be indexed completely.</p> 2. <p>Today we’re introducing new <a href="https://support.google.com/webmasters/answer/6144055" target="_blank">locale-aware crawl configurations</a> for Googlebot for pages that we detect may adapt the content they serve based on the request's language and perceived location. These are:</p>
So, the takeaway is:
If you decide to take the plunge and use smart quotes on your site, the Smart Quotes For Smart People website is a handy resource for how to properly use them. And make sure you're using UTF-8 to prevent encoding issues; but you were doing that already, right?
Note: You may have noticed that this article is using boring old plain quotes. I started the conversion from straight quotes to smart on this website during a recent redesign, but there are still several pages (including this article) that haven't been updated yet. It's a big process to change them all.