What are your goals?
I am speaking about campaign-specific, in this case. When planning on marketing campaign (acquisition. lead generation, fundraising, etc), the success of the campaign is obviously determined by the goals you set for it. But that's not always as straightforward as one might think.
At an organization I used to work for, we did semi-annual direct mail campaigns to acquire new groups (church youth groups) for a fundraising program. The obvious measure of success was, did we meet our goal of signups from the campaign? But it wasn't that simple. A lot of costs go into a direct mail campaign, among them list rental, postage, packaging, printing, creative, and so on. One of OUR measures was cost per signup. As a nonprofit, we were very conscious of how much we spent per each group we acquired.
For one campaign, we decided that sheer volume of signups was LESS important than cost per signup, driving for better fiscal efficiency. We went with a much simpler mailing with fewer components (lower printing and creative costs, but possibly less effective marketing), and made up for it with a larger envelope (of course increasing postage cost, but more likely to be noticed by the recipient).
The result was a 15% DECREASE in the number of groups we acquired, but a nearly 40% decrease in the cost per group. We had fewer groups to work with. But ultimately, a greater amount of money overall went to the cause.
So sometimes less really is more. What are your goals?