I click on that banner ad to visit a hardware site and review information on their available drills, then I realize I won't have time for it to be delivered by tomorrow, which is weekend and I want to complete those deck repairs before Monday. I'll run down to hardware store for drill purchase. But I fill out contest entry for giant tool giveaway before I leave their web site.

I return to my online book seller following week to look up a book my wife is interested in about flower gardening and buy it for her. Based on my previous purchase of cookbook and combined with this purchase CRM software figures I enjoy cooking and gardening and serves up an ad on confirmation page for a Martha Stewart video on vegetable gardening. I'm not interested in that and jump over to Yahoo to look up latest sports scores and I'm served an advertisement for barbecue grills.

Perfect, I'll order that now and it will arrive by time we're ready to enjoy newly repaired deck for 4th of July. I click on ad banner and complete barbecue purchase. I'm looking for a way to make weekend perfect, so to I decide to order flowers delivered to my wife.

When I complete that purchase, I'm served an advertising banner for a newly released relationship book. I click on that banner and end up back at bookseller site. Their software sees a return customer that is interested in cooking, flower gardening and love. At same time Yahoo sees a customer interested in sports thrills, reversible drills and barbecue grills.

Now both of those parties, book seller and Yahoo, have a different picture of my surfing and buying habits.

The book seller is incorrect because I haven't bought a single book that interests me. Yahoo has me pegged, but guess what? The only value they have gained is increased ad revenue, which only benefits companies that generate huge traffic and create unwavering visitor loyalty. What if I switch my home page to iWon from Yahoo?

The return on investment is negligible unless site enjoys record-setting traffic levels and commands complete customer loyalty. Who's buying this software? It's bought by global corporations. Who's selling? Really smart cookies.

On other hand, virtually all true marketing experts preach about importance of testing your advertising and marketing. Yes, marketing "geniuses" are usually very big on testing! Why?

Because even professional marketers often find it very hard - if not impossible - to predict how prospects will react in a given marketing situation. So even if you have some marketing savvy, testing can show you how to boost response that much further.

You don't have to be able to write a perfect sales letter on first draft, or second, or third. You don't have to instinctively know what most profitable price is for your new product or service. You don't have to guess which of your potential headlines will pull most response.

By scientific testing, true value of all theories, opinions and educated guesses are laid bare. If they truly contribute toward marketing success, testing will prove it. If they don't, testing will prove that, too.

In short, you don't have to be a literal marketing genius to generate better response from your marketing efforts. Nor do you have to listen to marketing advice of others, which may be inaccurate and unprofitable, although well-meaning.

Your prospects and customers can show you exactly which marketing approaches are truly most profitable in above areas, and many more, if you only test.