For startups, finding customers can be a big challenge. Even if a business has a steady clientele, many still seek that "silver bullet" for finding lots of customers quickly and inexpensively. 

So what's the trick? As sales expert Perry Marshall explains in this video, it really depends on your specific business. 

Many entrepreneurs wind up paying for ads on Facebook and Google AdWords hoping that the results will get them lots of customers fast. These platforms can work well for some companies, but not for all. 

In connection with his two books, Ultimate Guide to Google Adwords and Ultimate Guide to Facebook Advertising (both from Entrepreneur Press), Marshall created a pair of handy tools: Is AdWords For Me? and Is Facebook For Me?. Each asks you 10 questions and aims to determine whether those tools might be best for finding new customers for your business.

Weeding out lots of random or one-off customers in favor of your "best" customers speaks to the 80/20 rule of marketing and sales. "I don't think you really understand who your customer is until you're really clear about who your customer is not," Marshall says.

Related: 

'Rack the Shotgun': Using the 80/20 Rule to Identify Your Best Customers

The 80/20 Rule and How to Supercharge Your Sales and Marketing

80/20 Sales and Marketing: The Definitive Guide to Working Less and Making More (Related Book)