How many people take random breaks from their normal monthly ads to see where the company stands, maybe not even a month maybe just a week or two? We are in the middle of doing this now after a few changes to the site and I gotta say I am a little nervous to see how it goes.
Please your clients & thank them from time to time.......they are just like groupies that keep the band going strong.
We normally don't take breaks and don't have ads, right now most of our client tele is from posting threads on WHT, HD and a number of other forums. I know once we do some ad advertising then we will see even more signups, but right now where we stand posting threads ever week its going well.
Similar to Steve we do A/B split testing, however we do take breaks from certain networks when doing other testing - or we slow down a campaign on Google Adwords with a higher focus on another Campaign. So instead of having a Wordpress campaign we might spend less on Wordpress and increase the Drupal campaign. Rarely do we ever suspend all our campaigns unless something big was happening internally where we wouldn't be able to handle the new clients for whatever reason.