The way many search engines work is that a higher quality score receives a lower CPC. Maintaining a quality score of 6 or higher means that you can receive discounts of between 15 and 50%. This means that the higher the score, the more budget you have for your PPC campaigns. Cost-per-acquisition is the only thing that matters when it comes to bidding costs on a given PPC platform.
Consider how important it is for your ads to rank high and determine if the additional cost associated with ranking first is really worth it in terms of conversion volume. Now that you have an idea of how much a single conversion costs for your business, it's time to analyze what your bottom line is. Advertisers generally won't be willing to bid huge amounts that could sabotage their acquisition costs. Cost-per-thousand inevitably means paying for an indefinite number of page impressions from people who ignored the message.
Cost-per-thousand is good for brand recognition and product awareness, assuming that page visitors at least see the logo and, albeit unconsciously, absorb the message. For most Google advertisers, the cost per lead or customer acquisition will not exceed the bottom line. And if your average cost per acquisition isn't close to your margins, bidding higher means getting more conversions with hardly any additional cost.