Webinars have become trendy these days. To entice viewers to sign up as well as watch the entire webinar you have to offer something that when the viewer ponders the question "What's in it for me?" His answer will be "plenty." If your invitation to the webinar has the fingerprints of an aggressive copywriter all over it you're going to decrease the number of attendees.
Don't turn your webinar into a sales pitch. Some people will be bored while some will be resentful and they will simply exit the webinar. It's not like sitting in a convention room and having to awkwardly walk out of the conference while hoping a representative of the host won't stop and say "Where are you going?" They will simply "click you off."
It has been estimated that less than 10% of people who participate in a webinar are prepared to sign on the dotted line. Don't focus your seminar on your specific products or services. Don't instruct your sales team to contact the audience immediately after the conclusion of the webinar.
Offer a presentation filled with interesting and unique information that will establish your company as an exceptional source of information. This will create a rapport and a trust with potential clients. The delighted attendees will actually be promoting your webinar and your company to other potential customers.