I've just been thinking, I really haven't tested it, but does anyone here know if an image ad makes more than a text ad or the other way around? Thanks
Allowing both text and image ads should get the highest payout. Google will display the highest paying ad on the spot (determined by CTR * CPC), whether its an image or text. Allowing both text and image ads allows for maximum competition of that space. Chances are if you pick just one or the other, text ads will pay more because there are more advertisers using text ads so there will be more competition.
Additionally - text ads can be blenden well with the content, better than images, so this can give you higher CTR.
Image ads work well for me but seem to pay out the same as text ads on related websites - which is strange as the advertiser does pay more!
Image Ads have better CTR as per my observations but text ads still pay more per click as compared to image ads.
One thing to consider... An image ad usually fills the block with one ad - thus one choice. Text ads - say a 728 wide block - have 3 or 4 separate ads. That's 4 choices / 4 types of bait.
Another consideration, depending upon your layout and content - an image ad can enhance your page visually. Of course, that depends upon the creativity of the advertiser.
It depends.. Normally, Text ads gets higher CPC but low CTR in respect of Image Ads.. and, Image Ads have higher CTR but low CPC.