Inkling, which develops digital textbooks for the iPad, has been around for a couple of years now, but this year its been steadily building up steam (or at least cash) as it prepares to dramatically expand its offerings this fall. Earlier this year it secured funding from Pearson and McGraw-Hill, and today it announced a second round of funding from several investors.
Inkling’s approach is to augment textbooks with interactive, social, and annotation features, then sell them by the chapter for $3 each.
The approach may or may not be cheaper–CEO Matt MacInnis says it can end up costing a quarter the price of a new textbook, but I’m sure the savings are less predictable than that–but it does introduce a way of amortizing the cost of course material over the semester.
The company currently offers about 50 titles through its iPad-only app, and plans to have about 100 titles by the end of the year.