Let's assume you are split testing 3 different ads in your Adgroup. Should you tick the "Automatically optimize ad serving for my ads" option in the Campaign settings? How does this aspect work exactly? I fear that if I choose this option, each advert will not be shown enough to have a statistically valid test and therefore I may not have the best advert shown. Comments?
Ass soon you create/edit an ad Google System will test the ad CTR for all your keywords in the group and will test the CTR% effective of this ad compared for the other ads. The system will give more priority (serve ads) for the keywords that this ad has best CTR% performance (Virtual AdGroup). This option may have be enabled always with the following exception: that you will closely monitor weekly conversion performance for your ads. Otherwise enable the option. What do you mean? Do you have 3 ads for 3 different advertises for the same adgroups? If this is the case this is not recommended: Create separated campaigns for different advertises even initially you will have repeated keywords for these advertises. Each adgroup may have 3~9 different adgroups for the same advertise. So the system will select the best performing ad during the time - after some time you delete bad performing ads and add new ads based on top performing ad with small changes.