Your Marketing Sucks - The Hard-Nosed Guide to Implementing ROI (Return on Investment) Marketing" by Mark Stevens (published 2006 by Crown Business).
Stevens starts the book with "If the moola you spend on marketing isn't growing your business and bringing in more moola in return, then you have marketing that...sucks".
The author urges us to look at every marketing expenditure, and measure its impact. If it isn't generating more revenue than it costs, then abandon it - it's bad software marketing.
"Your Marketing Sucks" describes extreme marketing, a non-linear process in which all aspects of your advertising and marketing are integrated. Measure the effectiveness of each element of your advertising and marketing campaigns, and ensure that they're contributing to your profits. It's easy to measure the effects of the upgrade emails that you send to your existing customers. It's harder to track the effectiveness of your press release campaigns. Software developers need to make the effort to quantify all of their advertising and publicity campaigns.
Take bold and sometimes outrageous steps, Stevens insists, but be sure to measure the financial impact of everything that you do. Continue to do only those things that deliver a profit.
"Your Marketing Sucks" is written for larger companies - firms that spend serious money on television and print ads, and whose sales volume makes tracking results easier. But the principles also apply to independent software developers' companies.
microISVs need to have a marketing strategy - a clear statement of their firm's growth and profit goals. They also need a plan that ensures that their software marketing efforts support these goals. The book doesn't describe some of the advertising vehicles that are popular with software developers, such as banner ads, search engine keyword purchases, software registration incentives, or software upgrades. But it's easy to translate "Your Marketing Sucks'" principles into the day-to-day world of software application development and marketing.
I recommend that you buy the book. The chapter on picking the low-hanging fruit will more than pay for the price of the book, and the time that you'll spend studying it. It's good software marketing to learn ideas like these.