A simple improvement to Google’s search engine several years ago has morphed into a marketing technique that you may welcome or hate, depending on your perspective. Now it’s going a step farther, and, again, some people will fear it, and others will find it useful.

You’ve probably noticed while visiting various websites that pop-up ads relate to your recent online searches. A quest for low airfares to Florida, for example, may generate ads for Florida hotels and restaurants, no matter what website you’re on. This is predictive search, and it’s rooted in Google’s introduction of autocomplete in 2004.

When a user began typing a query, Google offered suggestions on how to complete that query based on common searches. The tool helped users search and find faster than ever before, but it also provided marketers with a way of targeting online advertising.

Google already sends reminders based on your location, established by the GPS on your smartphone. Soon it may be able to generate personalized messages based on a review of your personal information, emails and text messages. It could result in messages as useful as “there’s a traffic jam two blocks away,” to others that are more invasive.

As Yahoo News notes, predictive search is neither creepy nor cool – yet. Cool would be reminders such as the traffic message above; creepy would be reading your emails and your partner’s and advising divorce.

While this seems unlikely, it’s a real possibility down the road. Considering this, which camp are you in? Creepy or cool?