If your business is purely transaction based (think online eCommerce) look into your customer service, product, delivery and pricing.
If selling is more complex with a long sales cycle requiring solutions and consultative based focus, find the commonality of each person’s selling process and then the linkages between each step. Do they have a process? Do they complete each step before moving on to the next step?
If your sales operation has migrated to a CRM and an inbound marketing methodology and sales are not above a 30% increase over last year, then look into adoption and usage. This is key: Are they using the software? Over 60% of the SMBs I work with have poor adoption rates. However, if they ARE using the software and sales are less then a 30% increase, then look to see if they are using a traditional selling process. An inbound selling process is not the same as a traditional sales process. Maybe they are scaring away the leads?
Whatever the sales problem there is always a solution