Whether a chief marketing officer (CMO) has $100,000 or $100 million in his or her budget, the question comes down to how the cash is spent. And according to a new report, spend is slowing with more pressure for marketers to prove returns.

Budgets have decreased from 12.1 percent of company revenue in 2016 to 11.3 percent in 2017, according to Gartner's 2017-2018 CMO Spend Survey. Marketing technology saw the steepest decline in investment between 2016 and 2017, with a reduction of 15 percent.

The technology, sometimes known as "martech,"is used by companies in various ways, including tracking customers' browsing habits on different devices and matching that behavior to buying. It can also be used to automatically place advertising on websites, a complex process that has been subject to fraud, and has also resulted in ads appearing next to undesirable content.