Link units are my best performing ads.

higher CTR.

Link Units:
- have very appealing sentences, often at the limit of clickbait, and often unrelated to the ads showing,
- can easilly be confused with navigation links, or table of contents,

Link units are my best performing ads.

On both desktops and mobiles?

I know I was getting greater clawback when I went heavy on link ads, so ya, I think they are tricksy to visitors and have a low CPC for a reason.

They do best on mobile. You have to be careful where you place them and not overdo it. Their EPC is the same as any other ad, and my clawback is usually less than 1% each month.

I guess that an advantage on mobiles, is that link units are loading faster than display ads.

Ember, How many link units do you have per page? How many ad units altogether?

On pages with link ads, I usually have three normal ads and one link ad, but it depends on the length of the page. On some pages, it's one link ad and one normal ad. Link ads never go anywhere near navigation links. I also don't put link ads on all pages, mainly just on high traffic pages. It really just takes some testing to see what works.

Roughly how long would a page have to be to show three ads and 1 link ad in your case? I've always found it hard to strike the right balance between length of article and number of ads.

Since link ads make the most money for you, would it not make sense to have at least one more (while reducing one of the ad units)? The other side of the coin, giving link units more exposure means taking away the opportunity of earning on interest-based ads which can sometimes offer hefty CPC. That said, I just feel the regular ads no longer offer good quality ads on a consistent basis. Nowhere near enough. The targeting can also be quite off, which might actually come down to that fact that ad inventory in my niche is no way near as good as they used to be.

Also, with regular ads, which sizes do you use?

I know that for lot of publishers, more ads = more earning, but that's another subject.

An issue I can see, with adding several link units, is a risk to have plenty of variants of the same sentence / link , and this might ruin the appealing effect of Link units. Just a thought.

^ I agree. I saw very similar links in both link units.

I stay well within the Chrome guidelines of less than 30% ad density. Well within. I don't put more than one ad link on a page because they tend to be duplicates. 336x280 is my best performing ad size. Always has been.

I have one responsive link unit ad unit and one responsive ad unit on each page. There are guaranteed clicks with the link ads, but most days I don't get any clicks on the responsive ad units. I think the average click through rate on banners nowadays is something like 0.04%, or one in 40,000 views. There seems to be almost complete ad blindness to banners, but people will still click on link ad units.

However, my success with link ad units is decreasing. It now says 'SPONSORED SEARCHES' above link ad units. Also, the targeting for link ad units always used to be very good - unlike banner ads, which are normally completely irrelevant to my content. Just recently that has changed and now the link ad unit descriptions are very vague. These two things have resulted in a lower CTR.

Maths problem: 1 in 2,500, but still a very low CTR.

However, my success with link ad units is decreasing. It now says 'SPONSORED SEARCHES' above link ad units.

If, identifying the ad units as advertisements is the cause of the decrease of your success, then it means this success was built on misleading visitors, and therefor unfair for advertisers. Advertisers accept to pay, for real qualified traffic. When ads do not look like ads (ad units , can easily be taken as navigation bar), this can lead to poor quality traffic for advertisers, and this is not surprising they don't want to pay for this.

That being said, it's highly possible other factors are contributing to the decrease of ad units performance.

I have one responsive link unit ad unit and one responsive ad unit on each page.

Me too, one at the top of the page, one at the bottom of the page.

I think the average click through rate on banners nowadays is something like 0.04%, or one in 40,000 views.

Really, the average?

To make it meaningful to me, for this last quarter my AdLinks have generated 63% of clicks with 37% to AdUnit, however the AdUnit has a tad over 50% higher EPC therefore at the end of the day earnings have been 50.8% AdLink and 49.2% AdUnit.

This has been pretty consistent all this year.

BTW, AdSense reports make no sense whatsoever when drilling down, major bugs everywhere for me.

Higher CTR

Link unit CTR is very different from normal ads. It requires 2 clicks to make money from link units. First click will load a page with all relevant ads and then the visitor has to click on the ad. The second click CTR is reported which usually is very high given the entire page is ads.

will load a page with all relevant ads

That's the theory. Nowadays, links in ad units, are very relevant, yes, but, most of time, ads showing next as not really relevant to the subject...