Digital marketing costs far less than print advertising, but are you getting what you pay for? According to a study in the Harvard Business Review, the answer may not be what you want to hear.

The study found that “up to half of paid media impressions fail to reach a marketer’s target audience.” That’s because many of the impressions are created by automated scripts – bots – instead of people. This happens most often when marketing departments look to cost as the deciding factor in placing ads.

“Too often, CMOs succumb to the pressure to keep costs down at the expense of their brand’s health or product sales,” according to the Harvard Business Review. “This is especially true in the age of digital media, in which the temptation to pay low rates often leads to wasting money.”

The Association of National Advertisers said the use of sourced traffic is a major part of the problem, yet nearly two-thirds of major advertisers “are only slightly familiar with – or completely unaware of – the concept” of sourced traffic, according to Bill Duggan ANA’s group EVP. With sourced traffic, a publisher pays a third-party vendor to send users to its site by advertising on other publishers’ sites.

More than half of advertisers surveyed by ANA are not even sure if their company’s digital buys include sourced traffic, which is “a fairly common practice in the ad industry.” That’s a problem because while using sourced traffic results in increased traffic, it is “not transparent” to advertisers and “may be less valuable” to advertisers.

“Another major concern is that sourced traffic results in an alarmingly high level of digital ad fraud in the form of non-human traffic. In the 2015 ANA/White Ops Bot Baseline report, sourced traffic had more than three times the bot percentage of unsourced traffic.”

Such impressions are certainly not going to fulfill the need of advertisers for accurate, actionable data.

According to a study by EConsultancy and Signal, brands need to “understand individuals and audience patterns – channel interactions and their role in the customer journey – what customers want and when they want it.”

The study noted that “first-party data from real customers is going to be the most useful. The opportunity is unique because first-party data is defined, collected and owned by the brand itself. The data can be more accurate and timely than that from external sources and it’s useful for short-term action as well as long-term benchmarking.”

First-party data is what brands collect for themselves, such as from their website or mobile app. Second-party data is first-party data that is shared between partners, such as an airline and credit card company. Third-party data is for sale by aggregators.

About 70 percent of the surveyed marketers and media buyers use first-party data while nearly 60 percent use third-party sources, the EConsultancy and Signal study said. Third-party data is for sale by aggregators — but while it’s readily available and wide-reaching, its quality “varies widely,” the study found

“Unless organizations can rely on their numbers and what they mean, learning is inhibited and data never makes the leap to information and ultimately knowledge,” the study said.

Interestingly, organizations with strong ROI are more aware of the challenges involved in data quality and availability, it said.

Another data element that is often inaccurate is target location, according to a study by ThinkNear, which found that only 14 percent of a brand’s mobile budget “hit the intended targets” because the impressions were served outside of the desired target.

“If the location data used to target and serve ads is inaccurate, then the campaign will target users that are farther away, which causes waste simply because people are only willing to travel so far for restaurants or retail outlets,” the study revealed.

The Harvard Business Review study suggested that mobile advertisers fully vet potential partners to make sure they are “committed to being transparent about every shred of data and every penny of cost.”

In addition, advertisers should ask for “CPMs (cost per thousand rates) with performance right next to them. … To truly manage your media investments to ROI, you must manage your cost based on real impressions and business outcomes, not poor quality disguised as low cost.”