The #1 mistake technology companies make when advertising or promoting a Web seminar is that they sing the praises of their product, service or Web site ad nauseam, and forget to sell the event.

Whether print or online, keep in mind that your invitation has one objective only - to get people to register for the seminar. Don't load your copy with superlatives about how wonderful your product is and then mention the event as an afterthought. Even if your product sounds like the best thing since sliced bread, if the reader doesn't want to participate in the seminar, you've failed. Period.

Sell the benefits of your product only in the context of the event. Rather than "our online service enables you to cut procurement costs by 50 percent," say "Register for our free Web event and you'll learn how you can cut procurement costs by 50 percent." And so on.

Secondly, be sure to provide enough detail. Because campaigns often get designed long before the actual seminar has taken shape, the agenda can end up as an afterthought. Yet, the agenda will be a critical factor for many prospects in determining whether they register for the event.

If you're designing a print invitation, beef up your agenda by doing more than listing times, speakers and topics. Add bullets that describe what the reader will learn in each session. (Remember, don't focus on the benefits of the product or technology, but on the benefits of the material to be presented.)

If you're promoting the event via e-mail or a newsletter ad, you likely won't have the space for a complete agenda. So make sure that when the reader links through to the registration form, there's an option to view more detail about the event, including an agenda, speaker bios, and additional information about your company.

The sheer number of Web seminars mean that many companies resort to promotions - drawings, free gifts, etc. - in order to help drive registration. If you're concerned that promotions may dilute lead quality, consider introducing the offer only at the registration stage (on the splash page, for example), limiting eligibility only to those people who actually participate in the event, or choosing a gift that suggests some minimum level of interest (free product, for example, or a book on a related topic.)