Your A-Player employees, your stars, your top performers...don't always stay A-Players, stars and top performers. BusinessWeek has some more discussion on this.

Your company changes. Your means theirs and yours, together: new products and services, new technologies, new billing procedures, new taxes, new markets,  new competitors, new colleagues. And those skills and motivations that made them your A-Player, your star, your top performer... now make them a C-Player.

And your company grew because you had A-Players. The more the merrier, the more the growth. And now... your growth and by comparison their lack threatens your companies continued growth.

You have no choice. You have to invest in your employees to renew and re-inspire their motivation, to re-engage them, to communicate the vision, to connect it to their jobs and their day and their goals in a way that can answer these universal Three Questions:

• What's in it for them?
• Why should they believe?
• Why should they care?

I offered 16 ways to invest in your employees and they won't cost you a dime at AMEX's OpenForum.

And then there's the training to keep their skills current. By current, I mean it empowers them with the resources to accomplish their goals, to earn recognition and respect among their peers, to accomplish the goals to fulfill the mission, to provide them with growth opportunities or drive their growth opportunities as their success drives their company, your company.  And you maintain your stable of A-Players, stars, top performers.

What's often not discussed is sometimes, your original A-Players want to remain A-Players... for your original company. Said another way... they're comfortable or their discomfort with personal and professional change is greater than their discomfort with the impact from not embracing the change that happens all around them.

And your choice is do you allow their avoidance of change to keep your company as an A-Player of yore... or do you continue to attract and motivate and inspire and train A-Players for your company of today... and tomorrow.

Jerry Yang's departure as CEO announced today is a sign that... maybe perhaps, his ability to lead by example as an A-Player has passed. The markets think so. Yahoo's market value increased by over $2 Billion in pre-market trading on the news he's stepping down.

Disclaimer: Jerry Yang will always remain an A-Player for bringing Yahoo to life and steering it to its dominance of years past. I'm not one heaping on him here. But things change, markets and industries change. Companies change. Expectations change. Together, they demand different skills, different communities, different leaders. All good things come to an end, just like bad things will pass, too.

I've shared some tips, tools and resources for hiring A-Players in my ebook: The Collaborative Hiring Process: Tips and Resources to Create Your Own Wave of Success.  So, when you reach that point, you need new A-Players from outside... here's some tips and resources that brought great success for me in finding A-Players.