Online marketing succeeds with conversion. Moving up in search rankings is a critical step. Enticing people to click on your listing is another. But getting the lead — that is a culmination of efforts. And design plays a role in making it happen.

All of the time spent nurturing organic rankings and money spent on pay-per-click campaigns can quickly be flushed away on a poorly designed mobile landing page.

You cannot assume that your landing pages will be helpful...