This is one of the most powerful ways of getting people to drop in. You might send out press releases. On the Internet there are things like the List of Lists that accomplish the same function. A common trick is to get your business mentioned in print in a regular newspaper story. And if you can do it without being too obviously commercial, mention it in your remarks.
Many businesses find offering discount coupons brings in the public.
Put a special offer on your newsletters and emails, and in it invite people to pass it along to a friend. A free consultation or a discount on your services or programs are good examples, and you can even include a reference number that's tracked by software on your web site. Paid advertising is the lifeblood of ordinary commerce, and it works in Cyberspace as well. Just like ordinary advertising however, it's not cheap. Still, most businesses find paid advertising is a necessary expense that pays for itself.