4? Pah!
I've seen 21 on a page.

a page with 21 ads that comply with adsense policy?

He didn't say that last part.

Let me rephrase..
When does adsense decide a page can display more than 3 ads?

a page with 21 ads that comply with adsense policy?

No.

And above each block, it was asking people to click on the adverts!

It took over 3 months before Google acted upon it.

And... they were reinstated. Can you believe it? I couldn't.
And the first day they were allowed back in, they had 5 adverts showing per page (this time from two accounts.)

This time, Google acted quicker (less than a day) but they still have their account.

Gobsmacked is an understatement.

Let me rephrase..
When does adsense decide a page can display more than 3 ads?

The rules do not allow more than 3 adverts. Just because the system *may* allow it (for whatever reasons or glitches) doesn't mean you should try.

It may be because someone is using DFP. Who knows. Who cares? I just care about my account.

So we all agree it's a gleach, and maintaining the account is more important.

no chance there is a different policy/rules for really long pages for example?

no chance there is a different policy/rules for really long pages for example?

No.

I'm currently running another ad network that partners with DoubleClick Ad Exchange "which allows to offer additional advertising space to the three that Adsense allows currently." That's his quote when he asked me to sign up.

So I have 3 adsense ads plus 1-2 ads from them running on a page.

I used to run 3 ads per page on most pages. Now I only run 2 and have not seen any clicks/earnings decline. That's likely because the 3rd ad was pretty far below the fold on my pages. So I think as most of us know, it's not the number of ads - it's the placement of ads that really matters.

Currently I am being allowed to run 5 ads per page through out the entire website where just a year ago I was only ever allowed to run 3. I never really understood why but I don't mind it one bit. I've been using Adsense for almost 7 years now.

DirtyHarry, did they give you a special permmision?

Currently I am being allowed to run 5 ads per page through out the entire website where just a year ago I was only ever allowed to run 3.

What do you mean, you've been allowed? Did they write to you and say yes? Or is it a case of you adding 5 blocks, and they all appear?

I just made a test page and added 5 blocks. They all appeared, but that doesn't mean I am allowed.

I never really understood why but I don't mind it one bit.

If the latter to what I have just said, it's because you haven't been caught.

I've been using Adsense for almost 7 years now.

Means nothing.

It appears that Adsense has "silently" changed the limits of total ad units per page. It used to be 3 but now you can place up 6 ads for content units. Im not sure if this only applies to big publishers. Per Lamewolf's test, he is also able to display more than 3 ads.

Could someone confirm this?

That's why I started this thread in the first place, i had (by mistake) 4 ads on a page.
It looks like silent agreement to me too, it is very easy for them to auto block it.

It's not a silent agreement. My guess is, it's because of DFP, where you are allowed to compete with other networks. Because of that, they've had to alter it. But that doesn't mean you're allowed.

Best way to test it is... add five blocks, then report yourself to Adsense. See what happens.

I think we are allowed. If not, the remaining ads after 3 will remain blank but not anymore. A few websites have written about this "silent" change.

Perhaps someone here with reliable source could confirm it.

Or just ask adsense support...
once I added am ad in position fix, and they said I need to change it, so I asked them why mashble.com can do it, and adsense support replied it was "experimental"

DirtyHarry, did they give you a special permmision?

No, I never received official word from Adsense that it was allowed.

What do you mean, you've been allowed? Did they write to you and say yes? Or is it a case of you adding 5 blocks, and they all appear?

No, I never received official word from Asense that it was allowed. I actually have 6 blocks on any one page.

I just made a test page and added 5 blocks. They all appeared, but that doesn't mean I am allowed.

If the latter to what I have just said, it's because you haven't been caught.

No I don't think that's the case. I actually have 6 ad blocks on all my pages and only 5 appear. I do this because there are different elements of my site that load first on different pages so I kind of have to do it this way. I've been running 6 blocks for almost 3 years and only 3 ad blocks ever appeared. Now all the sudden starting sometime late last year 5 blocks starting showing up.

I'm anticipating that I will eventually allowed to display all my 6 blocks. That would be my personal max anyway.

I've been running an honest Adsense campaign on my website ever since I was accepted into the program. So I got nothing to hide or be concerned about.

P.S. I'm running plain Google Adsense. No DFP at all.

Well you're the one calling yourself DirtyHarry.

Personally, I wouldn't take the risk (and actually I find I get much higher EPCs where I run only two ads anyway, not to mention the potential organic search implications...) But keep it up, and if you're lucky, you won't get the boot.

Thing is ... even if it is allowed, google still hasn't updated their TOS in regard to this. It still says the max of 3 ad units per page.

Just check the "Policy violations" link in AdSense and it reads "You have no policy violations on record. Thank you!"

Also I did some searching and it seems like who ever can run more than 3 ads might actually have a Google AdSense premium account. I was officially invited some time ago to use DFP by Google Adsense. I currently do not use it. In my messages there is also tip (from May 29, 2013) that reads "Use DFP Small Business on my_site.com to grow your AdSense revenue" but I still haven't gotten a chance to learn and use it. I think I might be cheating my site from extra revenue because of this.

(An AdSense Premium account has nothing to do with DFP, just so you know)

The only people who can tell you for sure that you're in compliance are the ones who work at Google in the AdSense dept. That's it. And despite what people seem to think, Google doesn't know all and see all. They don't instantly know if there's an infraction or not. So just because it's running doesn't mean it's compliant. If you want to know *for sure* then you have to ask Google, and run the risk that they will tell you that it's not. Or they might tell you that that it is and they haven't updated the TOS recently. Or you could just leave it alone, and maybe they won't ever notice, and maybe they will. But nowhere are you going to get a definitive answer except from Google.

In response to Mo_T

I decided to check on where my ads are originating from and here's what I found. I'm getting three different addresses that are serving ads to my website.

www.googleadservices.com
googleads.g.doubleclick.net
ad.doubleclick.net

So of the six (6) ad unit placements I have on my site, I get a random mix of the three ad servers I listed above for five (5) different visible ad units. I'm not using any other code than plain asynchronous AdSense code (from [google.com...]

P.S. I'm really loving the 12% increase in ad revenue that I'm getting after Google's most recent Adsense optimization tip I received last week.

Good luck OP.

To answer the OP's question:

Premium accounts are allowed 4 ad units (maybe more?).

A website might have another ad network in addition to Adsense that uses Adsense as filler/backup ads, in which case you would see more than the 3 ad units on one page.