<p>Not much use in closing the question now; at present, it's 11th most popular, and poised to continue climbing. I shared that initial impulse though, FWIW. I find its popularity useful for redefining the utility of CV as a whole—not that it needed redefining necessarily, but I think I understand it better now, thanks to this question.</p>

<p>As for <a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a>, one question certainly doesn't make the tag needed. <a href="https://stats.stackexchange.com/search?q=facebook">Searching for "facebook"</a> yields 66 hits at present though, so if <a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a> is going to be useful, it should probably be applied to some of those other questions (of which there are less than 66, because that number includes answers). That being said, those questions may not be <strong>about</strong> Facebook, so if too few of the questions actually are, the tag seems quite useless from an empirical perspective, for now.</p>

<p>Furthermore, since <a href="https://stats.stackexchange.com/questions/tagged/social-network" class="post-tag" title="show questions tagged &#39;social-network&#39;" rel="tag">social-network</a> already exists, has been used 21 times, and has a good, non-redundant wiki and excerpt (<a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a>'s are redundant), the synonym suggestion,<br>"<a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a>$\rightarrow$<a href="https://stats.stackexchange.com/questions/tagged/social-network" class="post-tag" title="show questions tagged &#39;social-network&#39;" rel="tag">social-network</a>" would naturally find its way to a meta-question like <a href="https://stats.meta.stackexchange.com/q/1200/32036">Current tag synonym candidates</a>, by my own hand if no one else's.</p>

<p>Since the preceding answers argue for this synonymity as well, and have received their share of upvotes already, I've submitted an edit to the question in question that replaces <a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a> with <a href="https://stats.stackexchange.com/questions/tagged/social-network" class="post-tag" title="show questions tagged &#39;social-network&#39;" rel="tag">social-network</a> (among some other pretty trivial changes). It got accepted, so I guess that's that? <a href="https://stats.stackexchange.com/questions/tagged/facebook" class="post-tag" title="show questions tagged &#39;facebook&#39;" rel="tag">facebook</a> now appears on zero questions! I suggest it be removed entirely...though <a href="https://stats.meta.stackexchange.com/a/1162/32036">this will happen automatically if it remains an orphan for six months</a>.</p>

<p><a href="https://stats.stackexchange.com/questions/tagged/social-network" class="post-tag" title="show questions tagged &#39;social-network&#39;" rel="tag">social-network</a> might fit on some of <a href="https://stats.stackexchange.com/search?q=facebook">those questions that mention "facebook"</a> though, so there may remain some work to do, depending on whether editing those questions is worth bumping them up in <a href="https://stats.stackexchange.com/questions?sort=active">the active questions list</a>. This (and the OP itself) raise a number of related meta-questions:</p>

<ul>
<li><a href="https://stats.meta.stackexchange.com/q/441/32036">What should be rules for making and using tags?</a>

<ul>
<li>Note the tentative rule, <a href="https://stats.meta.stackexchange.com/a/452/32036">community consensus prerequired for sitewide retagging</a></li>
<li>@AndreSilva, note the proposed rule, <a href="https://stats.meta.stackexchange.com/a/449/32036">"adding new tags by retag should be exceptional"</a></li>
<li>Note comments on downvoted rule, <a href="https://stats.meta.stackexchange.com/a/456/32036">automatically kill one-question tags, except w/ high rep</a> </li>
</ul></li>
<li><a href="https://stats.meta.stackexchange.com/q/1622/32036">Is it reasonable to go tag-hunting?</a> [for the sake of retagging where a good tag is missing]</li>
<li><a href="https://stats.meta.stackexchange.com/q/1200/32036">Current tag synonym candidates</a></li>
</ul>
