Why Plugrush ads network is not SEO friendly?
 

Why they don't implement nofollow attribute in ads, have you check juicyads ads, you will see they are using nofollow attribute in ads, so Google pagerank is not pass to that URL, Also Google highly recommodend to use Nofollow tag in all advertising links but look's like plugrush technical team don't know anything about it.

If plugrush can't use nofollow tag like other adult ad network using then they can use robots.txt method as well.

Look out Google official Ad server i.e. Adsense.

As you can see they block most of bots including Googlebot, MSNbot etc, so pagerank will not going to pass, so that is other method for ADS SEO.

I really like if Plugrush implement that kind of thing, If any of plugrush team hear me then please implement this, and if you want to know more about this, then feel free to continue this discussion here.

Just add the no follow tag yourself:
How to Add NoFollow Tag - For Dummies

I am talking about plugrush ads, they are not using nofollow tag on ads, you can't add it manually, it is not links it is javascript and we can't host their javascript externally nor we can change anything on that.

p.s. I am not noob, I am managing lot's of website, may be today you have visited that website :)

Well if it's Javascript then why not use Jquery to select the different links and add it once it's on the website? Or make an eventListener which checks for external loading and them for all Iframe elements check if the links contained are with the nofollow tag? Or you can try some delayed (asynchronous) loading of the script, this way google bot won't see when fetching it? (This said, I don't know if googlebot takes in consideration asynchronous loaded ads or not, try to fetch like google in google webmaster tools and compare the two versions..). Hope this helps.

I have tested myself, you can even checkout this source, and read update note at last.

Google does not recognize rel attribute that is implement by Jquery, Jquery is useful for opening links in new tab. Google only look out on rel attribute, which we can't implement it though jquery.

How about thinking aboutside the box? Let's take a variable and this variable on you page contains the size of the screen of you site's visitor. Now this variable is passed to a php script which includes a prewriten add of plugrush. ('Just take about 4 différent sizes and copy paste the html into 4 différent php files.) Then you can make a request to the required size where you can easily change the link code now in advance. The problem here is mainly that I don't know if the thumbs, once they flip a reconstruct completely or not. (Is it a change of src or the addition of the completely new image element.)

This may not be perfect but probably the only suggestion I can think about. (Chances are height that thumbs will still flip if the code from plugrush is still able to find the elements it is supposed to create.)

Look's Iframe technique