Despite fears of a recession, many US marketers plan to maintain or increase their budgets as well as increase spending on search engine optimization (SEO), a new report has shown.

The second annual survey on direct response media conducted by Target Marketing showed companies are changing their "media mixes" to keep up with the changing habits of consumers.

It revealed many online promoters plan to spend more on email and search engine marketing.

However, the study warned that when the economy slows, firms seek to create the most value from their marketing efforts and target the methods which offer the greatest return on investment (ROI).

"With respondents selecting email as the channel that delivers the best ROI for retention efforts (37 percent), marketers should expect significant clutter in their audiences’ inboxes this year," Target Marketing noted.

Despite this, recent research conducted among businesses by online resource E-consultancy revealed that a "surprising" 47 per cent of respondents were unaware what the ROI of their email marketing is.