I know nothing about you or your business or business norms and standards where you work, so it would be difficult to tell you whether it would or wouldn't "work."

You could try it to see what kind of response you get.

It's a reasonably classic psychological sales gambit to lead the person on the other line to agree to something with/from you. You want to start discussion--"May I send you some information about my company?".

I assume you're going after clients who have no website, otherwise you might say something like "I'd like to offer you a free assessment of your website. If there are at least 3 points on which I believe I can help you improve the site to meet your goals, I'll call back to schedule an appt."

And, if you are going for firms that have no website, be sure to be prepared to explain why this might be important for their business.