Every sector in every country ever experiences this issue; the cost of an empty seat.  The impact to your business of having one cylinder in the engine not firing is that you are losing essential horsepower.  No where is this more true, or at least more evident and measurable, than in sales roles.  Last year there were 65,161 unique job postings for roles entitled Sales Manager.  

Its amazing that 60% of companies in the USA have openings that have been open for 12 weeks or longer.  Why?  The answer is diverse, complicated and subjective to an extent.  But one thing is 100% for certain, there are great search firms that could help.  

I have been surprised over the last few years to see how many companies simply roll into the market through their internal efforts and expect to find their ideal hire.  I agree that the technology available is better than ever (especially linkedin).  But the activity that happens before a role is posted, and to manage the nuance of a selection process, is where experience and talent comes into play.  We also can't forget the essential activity in staying close to candidates in their notice period and in the first delicate months of a new role.  

While I understand the desire to cut cost and take processes like recruitment in house, I don't understand how it makes more sense to leave a seat empty for 12 weeks or more.  Maybe 6 weeks, or some other milestone, should be set as tipping point milestone where a basic cost V benefit decision is made.  At that point the outcome would probably be that the cost of engaging a professional partner is less than the ongoing, indefinite and extended cost of the empty seat.