93% of web sites have problems with their ad tags, the pieces of code that track the performance of online advertising campaigns, according to a new survey of a couple of hundred senior level execs in online advertising, retailing and I.T. by TagMan, a vendor of technology that manages the tracking tags tied to online ads.

Too many tags slow down page loads, which results in retailers losing traffic and sales, says Paul Cook, TagMan CEO.

The survey also found that 86% of respondents say they have misused tags in various ways, such as loading a page with too many tags, which slows down traffic and can cause Google to lower its Google natural search ranking.

The implications of those tag management issues is significant, TagMan says. Among the effects, with the percentage of respondents citing each result, are:

• The loss of campaign performance data, 65%
• Delays in launch of a new campaign, 63%
• Delays in the use of a new marketing technology, 58%
• The loss of web site traffic, 31%
• Declines in web site sales, 28%.

Even though 23% of respondents said they spend more than $10 million per year on marketing technologies and services that rely on site tags, more than a quarter did not know how much they spend on I.T. resources to deploy those tags.

“Unless you are in the I.T. department, there is a tendency to gloss over the problems of ad tag implementation and management, taking for granted that somehow ad tags are easily added or taken away without cost or consequence,” says Cook. “But there are huge costs and potentially significant loss of revenue from poorly managed ad tags.”