<p>As commented above, as long as </p>

<ul>
<li>it's a one-off thing</li>
<li>there's explicit disclosure</li>
<li>the answer is a good quality one and stands on it's own</li>
</ul>

<p>then I don't think there's a need to remove the referral link. If the referral link is the only thing that's being blasted across - then you know <a href="http://meta.stackexchange.com/a/58035/133693">where &amp; how to make use of the spam flag</a>.</p>