Search engine marketing (SEM) is a booming industry. Paid placement, contextual ads, paid inclusion, search engine optimization and the rest of the SEM suite combined for an estimated $5.75 billion spend in 2005—with paid placement accounting for the largest slice of the pie at about $4.77 billion—according to a recent study of SEM marketers and agencies by the Search Engine Marketing Professional Organization (SEMPO).
That number is only expected to climb as the rise of local and niche search, increased broadband use and escalating cost-per-click rates drive the channel’s growth. SEMPO estimates the industry will ascend to more than $7 billion this year and summit the $11 billion mark in 2010.
So how are marketers tracking their investment in this steadily growing channel? As the chart below illustrates, SEM strategists are relying on a number of different metrics, with traffic volume, conversion rates and clickthroughs ranking as the most popular tactics.
—Tracy A. Gill