You can't force word of mouth to occur (trust me I've tried).

But when you're crystal clear on how it might occur, you can foster the conditions that will make it more likely (MUCH more likely).  Therefore every business interested in getting talked about should be able to thoroughly answer the 5 Ws of WOM:

WHO?  Who will be talking about you?  Your customers?  strangers?  Do you know who they are?  Do you have their contact information?  If not, can you get it?

WHAT?  What exactly would you like your customers say?  Now that you've gotten that of your system, what will they actually say?  Have you made it easy for them to explain who you are and what you do?  Have you thought about just telling them what to say?

WHERE?  In what locations (offline or online) will these interactions occur?  At your store?  At home? At work? On your blog?  Facebook? At the annual conference? 

WHEN?  Will these interactions occur on the weekend? Maybe at dinner time?  Will they occur when you send out a newsletter?  When your commercial runs?  Will interaction happen simultaneously like an in-person meeting or non-concurrently ike via e-mail?

WHY?  Why will people talk about you?  Are they financially motivated?  Are they socially motivated?  Do they need votes for the contest your running?  Do they believe in what you stand for?  Do you stand for something?

HOW?  Will they phone others?  Will they forward an e-mail from your company?  Or just write the URL in the e-mail themselves?  Will they blog about you?  Tweet about you?   Foursquare about you?  Will they push the facebook like button on your homepage?

Clarity is power.  If you can answer these questions well…bravo.  If not, you better get to work.