Prettying up an email marketing campaign can boost conversion rates, according to a study of best practices by Silverpop Systems Inc. Called, "Email Creative That Works," it analyzes 610 emails, including business to business and business to consumer, sent by 430 companies to 100 or more recipients.

While it acknowledges that targeting the right product at the right price to the right audience is critical, the study also confirms that creative elements add icing that can sell even a bland cake. Adding the company name or brand in the subject line, for example, resulted in open rates of between 32 percent and 60 percent higher than email messages that did not include this information in the subject line.

Lifestyle photography was also found to pay off in higher email click rates. In business to consumer emails with lifestyle photos, the average click rate was 6.3 percent, versus 5.4 percent without it.

The postcard design remains a favorite of business to consumer email campaigns, and it represents approximately 36 percent of the layouts analyzed. Yet it does not produce the highest click rates.

The newsletter format is the winner when it comes to generating click rates, according to the study. It produced an average click rate of 7.1 percent versus 6.2 percent for emails using the postcard layout. Silverpop Systems analysts concluded that online retailers and others should take a more serious look at newsletter email campaigns.

Dollars off deals were more appealing than offers of a percentage discount. Senders of email in the study most often featured a percentage discount in their promotions.

According to the study, click rates for emails that offered a discount of a specific dollar amount were 45 percent higher than those offering a percent discount. It became clear that shoppers find it more appealing to get $2 off a $10 purchase than getting a 20 percent discount.