Higher earnings per click when I have adwords going.

[I Will Make It]

It looks like I earn more per click from the ads on my page, when the people that click my ads comes from an adword campaign I run.

I had an adword campaign going on in February, then I stopped the campaign in March, and now in April I've started the same campaign again.

What I notice, is that almost immediately after restarting the campaign now in April, I earn much more per click than what I did in March when I didn't have no campaign going..
The numbers from February and April looks great, but the numbers from March does not look so great..

Is this wierd or do you think it is a coincidence?

[inbound]

It could be that (if the proportion of paid visitors is high enough) the 'quality' of traffic from Google is better than your average visitor. A person who clicks on an advert to get to your site is clearly not adverse to clicking on adverts.

On a low traffic site it could be as simple as that, especially if your 'free' traffic relies on searches which have many words in them. The likelyhood of a visitor finding an exact advert on your site to match a very precise 'natural' search is much lower than a 'broad match' paid search visitor finding another advert that is broadly similar.