Ya all know (or should know) that alot of sponsors have bonus days were they pay you $50 $75 or what ever per signup. (just signup for enough sponsors and you basically get daily a email about it ;-) )
Wouldn't it be great if you could update one file and update all your sites to show a banner to that sponsor for when they have a bonus day?
Well you could.
make a file one of your domains called mypromo.php (or what ever name).
Code:
<?php
echo'<a href="sponsorlink" target="_blank"><img src="mydomain/banner.jpg" border="0" /></a>';
?>
Now on every site where you want it to showup do this:
Code:
<?php
readfile('http://www.mydomain.com/mypromo.php');
?>
it will read the promo file and put what ever it outputs in your page (make sure the domain where you host the banner allows your other sites to hotlink it ;-)
Afcourse you can do what ever you want, text links or whatever.
and if there is nothing you wanne show ..
just change it to nothing
And voila next time you get a $100 promo in your email .. you change one file .. and all 768 sites of you running the same promo .. making you mad cash!
Now go think for yourself and realise you can do way more funny things with this ;-)