I often report numbers showing 22+ frequency and always wonder if it really true? Why are we showing the same Ad to the same person 22 times. Something is wrong with the data... but, if it is for every campaign it must be true. Probably, that is how it is...OK.
I was driving in downtown Chicago (taking my wife to the Yoga class), and guess what - I start seeing Zecoo trading's ads. First ad - I said "Hey, the brokerage account that I use for trading, cool!", the next minute I see 3 cabs with the same ad for Zecco trading, I thought great! they are really try to acquire new customers. Believe it or not, in my round trip of less than 2 miles, I saw 8 Zecco trading ads. At the end of the drive, I was like OKAY! I get it, Zecco trading is offering 10 free trades and I use them every month. Forgot to mention... I see their online banner ads during the day at work.
The above is a classic example of over saturating the market with ads. Advertisers need to realize that there are only "n" number of consumers out there in the market. By spending more money, we cannot increase our market size. The more money the advertisers spend, their expectations for returns also go up. Is that justified? No! By showing more ads, you are reaching the same consumer audience and you cannot force them to start using your service or buy your product.
In my experience in the online world, 4-6 Ads bi weekly per user should be the ideal frequency. If a consumer does not convert due to exposure 4-5 times, chances that he will convert with 22 views are also very slim :)