They can not. If I am a manufacturing company, the mfg company makes machinery, and the sales model uses inside salespeople, directs and distribution. getting updates from the in-direct sales team is time consuming and hard at best and is impossible to do in most cases.
This is impossible because to tie in the in-direct sales person costs user fees and training costs and support costs. Look at salesforce.com. This service is 65 usd and up per month per user. Many distribution branches, like Xpedx in Dallas have over 10 sales people to provide logins for this user base costs over 600 usd per month. Plus the distributor sales people are busy. They sell all day and do not have time to enter lead and opportunity updates into a hard to use CRM. This cost is only for one distributor. Many manufacturers have dozens and others hundreds of distributors. The cost of using a CRM tool to get simple lead and opportunity updates is too high.
This causes the marketing and sales department at the manufacturer to set strategy with eyes that can not see. The visibility to what is happening in the sales territories is zero. The only sales data that is gather is orders. Sure this is important but is only one piece of the sales process.
Sales managers which have no access to sales data are not even baby sitters. Baby sitters are expected to keep the kid out of trouble, to see the toddler crawling to the stairs and change direction before the hard fall. The sales manager that only operates off order data is handuffed, he can not plan sales strategy and he can not guide the sales ship through rocky shoals or slow periods.