space advertising
...that there have been several proposals for space advertising projects, including a giant, 1km² billboard visible from Earth?
...that there have been several proposals for <b id="mwCJQ"><a href="./Space_advertising" id="mwCJU" rel="mw:WikiLink" title="Space advertising">space advertising</a></b> projects, including a giant, 1km² <a class="mw-redirect" href="./Billboard_(advertising)" id="mwCJY" rel="mw:WikiLink" title="Billboard (advertising)">billboard</a> visible from <a href="./Earth" id="mwCJc" rel="mw:WikiLink" title="Earth">Earth</a>?