Hi!

I've managed to put banner after every third post in main blog page.

I did it through ATO Style and edit center column and there I added

<?php if ( $bfa_ata['postcount'] == 3 ) { ?>
...banner code...
<?php } ?>

So, there it says that if I put something like <?php if ( is_front_page() AND $bfa_ata['postcount'] == 3 ) { ?> it will show only on FP.

And what would it be for single post page?

Thanks!

you will need to use one of the other conditional tags. Take a look at this http://codex.wordpress.org/Conditional_Tags

Wow, I made it! Thanks a lot juggledad!