Implied hCards attempt to streamline creation and markup for simple hCards by assuming information from common design patterns.
As microformats grow and emerge, the barrier to entry for writing them increases. Already, compound microformats such as hAtom, hResume and hReview are comprised of data from hCard, hCal, and rel-tag, and writing to the former requires knowledge of the latter even if the constructs used are quite simple. In addition, adding microformats to a Web page often requires adding a significant amount of tags to code, which often have to be added (time-consumingly) by hand. For example:
<a href="http://www.example.com/">John Doe</a>
<span class="vcard"> <a class="url fn n" href="http://www.example.com/"> <span class="given-name">John</span> <span class="family-name"> <span class="sort-string">D</span>oe </span> </a> </span>
Which amounts to an almost 500% increase in code. For two words and a URL.