<p>If you count the how many times a link is used you know which are the most popular ones. You can count them using javascript or indirect links.<br>
If there are more than 10 (or 15) you put the less popular ones in subcategories or subcategories of subcategories or you get a long list clicking on a more button.</p>
<p>The links could be submitted by the community, probably someone having a look on it before publishing.</p>
<p>In the Wiki List of OSM Based Services are roundabout 300 different services. Some of them are only interesting in a special region, so you can deactivate them in the rest of the world.</p>
<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br>Reply to this email directly or <a href='https://github.com/openstreetmap/openstreetmap-website/issues/409#issuecomment-22001564'>view it on GitHub</a>.<img src='https://github.com/notifications/beacon/uTRSc6ihLa7Shf84BpiOpicHZfjluatPHxbnTd94CJlPs5dFWECQEOi5iwyH7ihK.gif' height='1' width='1'></p>