One of the features I love in
They can add some cool functionality to the tracker and can make reading stats easier.
You can add custom columns when you go to "Settings" -> "Stats"

Then you can use formulas to create custom columns for your stats.
I will start with my own custom columns.
When you also have some of them that you want to share just post them here 
Name: Conversion Value
Formula: revenue/leads

Description:
When I run campaigns with different offers it shows the average conversion value.
Name: CPA
Formula: cost/leads

Description:
Shows how much a conversion costs me.
Name: Click CR
Formula: leads/lp_clicks*100

Description:
By default you see the conversion rate from incoming traffic to the offer in
With the "Click CR" custom column you can see the conversion rate from outgoing traffic from the lander to the offer.
Name: Real CPM
Formula: cost/clicks*1000

Description:
Shows the real CPM that I pay.
Of course it´s not 100% accurate because of trafficloss, the better you set the % trafficloss, the more accurate the value is.
Name: Possible CPM
Formula: revenue/clicks*1000

Description:
Shows the maximum possible CPM I can pay to don´t make losses.
Very good when you want to check placements for WL campaigns.
@twinaxe thanks for this share.
I've setup these custom columns in my 
Glad when it helped already.
Would be great when others would share their custom columns as well 
Name: Cost LP Click
Formula: cost/lp_clicks

Description:
Shows how much you pay per click from landing page to offer.
This can be interesting to show the different click costs between pops vs push for example.