Remember when “cookies” were controversial? People complained about having their online activities tracked by these pesky little programs. Cookies, however, are nothing compared to the tracking technologies available to today’s marketers. Sophisticated tools enable marketers to follow your every move online and even in a brick-and-mortar store.

Having in-depth customer knowledge and the ability to pinpoint prospects so precisely is a marketer’s dream. But some of the latest technology makes me wonder if we marketers have gone too far.

Here are some thoughts on the pros and cons of tracking technology in marketing:

The power of targeted marketing. Targeted marketing is a powerful formula for success: Interested buyer + extremely relevant message = higher likelihood of a sale. This is why direct marketing has always been such an effective tactic.

The web has brought us marketing tools we never could have imagined. Thanks to cookies on the Zappos.com website, for example, a micro-targeted ad for a specific brand of sandals greeted me on the Washington Post’s website minutes after I viewed those sandals on Zappos.

How targeting benefits consumers. There’s a big upside to targeted marketing for consumers. When advertising is directly related to your interests, it’s more meaningful and makes buying easier. If you have a relationship with a brand — as I do with Zappos — you welcome ads, whether they’re on a screen or in your mailbox.

And the fact is, as consumers, we want to be engaged with marketers, and we’re happy to use technology to do it. We join loyalty programs and share email addresses to get coupons. We check in on Facebook and FourSquare. We download marketers’ apps and willingly accept user agreements, even though we know marketers are collecting data about us every step of the way.

Taking it too far with tassels. When marketers strike a proper balance and send you messages you welcome without invading your life, it can be the foundation of a long and profitable relationship. This delicate balance is one reason for the success of companies such as Amazon. But what happens when technology enables marketers to get a little too targeted?

Recently, an ad for graduation tassels appeared on my Gmail page. Why? Because my daughter is graduating from The Ohio State University and I have been using Gmail to send information about the commencement to family and friends. Having the text of my emails analyzed makes me uncomfortable. It’s sort of like applying NSA tactics to marketing.

Getting close to creepy. The New York Times recently reported on several new technologies that allow retailers to track your movements via wireless signals from your cell phone while you’re shopping at a brick-and-mortar store. The article also mentions software that retailers can use to send targeted offers to your phone as you shop in specific departments. Other technologies can use your phone to identify you as a repeat visitor to the store, while video cameras can analyze your mood based on facial cues. The technology is amazing, but does it cross the line into the realm of stalking?

A new responsibility for marketers. Delivering highly relevant messages to potential buyers at the exact moment they’re interested in the types of products and services you sell is a smart strategy. And marketers would be crazy not to use the best available capabilities to pinpoint prospects as effectively as possible. But new technology creates new concerns about data collection and privacy. Marketers have a responsibility to understand how customers will be affected by such tools and to know when it goes too far.

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Jean M. Gianfagna is a marketing strategy expert and the founder and president of Gianfagna Strategic Marketing which provides marketing strategy and creative services to leading business-to-business and consumer marketers. Read her blog for more marketing tips at http://www.gianfagnamarketing.com/blog.