At my work, we like to invest in companies that we think would be attractive LBO Candidates... Blackboard really fits the profile.
1. Entrenched business model
At my school we used Blackboard and we had about 50,000 students. Getting everyone on board to switch from Blackboard to a new system would be pretty tough. The university would have to spend a lot in terms of re-training which would make it tough for a new system to gain traction.
2. Recurring revenue stream
Blackboard has a recurring revenue stream which is pretty awesome for a private equity buyer. You see, the PE game is pretty simple. You buy a business for X, where about only 10-30% of X is actual cash you put up. The rest comes in the form of debt.
A recurring revenue stream is great in that your subscription fees can cover the interest payments on your debt and in many cases will allow you to have more debt as part of your capital structure than normal. Lenders will see that your business can generate a stable enough cash flow to support such large amounts of leverage. A business such as Blackboard could potentially support leverage that's on the high end of the scale because of its recurring revenue stream.
3. Ripe for cost cutting
A company like Blackboard is bound to have a good deal of fat that can be cut. Slashing R&D funding and whatever growth spending will increase the amount of cash flow that goes to investors. My guess is they will streamline the company to be more focused on its sales force than whatever developer-base they have in place at the moment.