Can I have a banner in 30 place of my website? Is this OK?

No problem no issue for banner submit.

Thanks.

So, no problem at all?

WTH is banner submit?

I'm assuming you want 30 banners on each page since there's about 500 million websites with a handful of banners on them and that's obviously not a problem.

With 30 banners on a page, this might hurt your on-page SEO, since the banners will be pushing most of the content down below the fold. For UXO, you want the content to appear as close to the top of the page as possible, this becomes a balancing act. That's why most internet marketers who rely on SEO as a traffic source use a minimal number of banners, or they just monetize the page some other way. The banners are utilizing valuable real-estate that can be used for better things, like attempts to build trust with the visitor. Also, it's been known for awhile that if you replace the ad unit in the "key position" when an opt in box, that you can generally generate more income off the mailing list. For CRO the banner ads are also distracting the visitor from your offers, so if you're doing affiliate marketing, I suggest you dump the banners.

I generally choose follow this plan when monetizing sites:

Goal of the site is to generate sales: zero banners, single opt-in box with clear call to action.

Goal of the site is to give away information or teach (most blogs): adsense or some other contextual advertising with more aggressive email boxes.

Goal of the site is generate high visibility via social media: CPM banners, taboola/outbrain, email boxes are replaced with aggressive sharing buttons.