You could have fooled me by the way people here bang on about it!
Yea, and though I walk through the valley of Healing Surges, I shall fear no Encounter Power; for thy Vancian Magic and thy Saving Throw they comfort me...
I am very familiar with Ryan Dancey's 'network externalities' method thank you very much. It still remains in doubt how much of an affect this had on WOTC's bottom line. Mainly, it seems to be that it opened up opportunities for the little guy to make a buck off of D&D, in addition to servicing the customer in ways that were too niche for WOTC to go after. The thing is, it also opened up the door for people to make virtually their own games on the back of D&D and this really didn't help WOTC at all. And that's even before Pathfinder came into the picture.
Here's the thing: IMO they don't have a hope of turning the heads of ANY of the Old-School Renaissance crowd, OR the Pathfinder crowd without using the OGL; those ladies and gents already have open access to material they like, and other publishers willing to offer variants for that material for them to consume, thanks to said license.
What's the importance of the license? You're correct, the majority haven't a clue what the OGL means to them; however, most every one of those groups have one or two die-hards, "proselytizers" (see, it is a religion when you think about it!) who actively do know and appreciate the OGL; they're usually the hard-core rules monkeys or DMs who use open content to expand options for their game; who dream of being amateur publishers themselves; who consume the high-quality 3PP content like Paizo, or Legendary Games or Frog God games, and who use open content to teach or introduce new players to their groups. These are the guys who grow the RPG community through grass roots, the "network", and whom WotC is currently actively trying to court favor with.
I still ask: If the loss of the people who moved to OSR games and 3E-based games isn't very significant to WotC's bottom line, then why the press releases specifically designed to court mechanics and concepts these groups prefer? Why the announcement only two and a half years in that a new edition is coming? Why the push for 4E Essentials barely a year and a half after initial release? Why the push for unification of the player base? To me the only answer that makes sense is that WotC is concerned with D&D's sales, and REALLY needs to get as many players past and present under one banner as possible; they don't like a fractured market any more than we consumers do. Me, I'd like to be able to get everyone appreciating every version for D&D for what it offers. Even better, but a very tall order, is getting the CURRENT version of D&D able to include ALL versions of D&D in its wheelhouse through rules modules, so to new players, we're not playing "Pathfinder" or "Swords and Wizardry" and confusing the heck out of them -- we're playing "D&D."
It's not exactly a good idea to give potential competitors the keys to the store (unless you are closing the store and abandoning the business completely.
Gilette thought it an awesome idea to give away the shavers; we pay through the nose for replacement blades, and it makes 'em money. Offer awesome products for free that drive people back to your core products, and you'll make money. Paizo repeatedly says their strategy (Ryan Dancey's strategy, according to Lisa Stevens) makes Paizo successful; their products don't drive people back to D&D, it drives them to the Pathfinder core books. 3rd party publishers are also driving sales to Pathfinder core books.
Savage Worlds seems to have almost the reverse philosophy; offer the rules cheap or free, and it drives people to their settings and tools. Heck, I own at least three copies of their Explorer's Edition, because I use it to teach people the system so they want to go off and buy it on their own.
Please your proselytizers, and they'll sell it for you; it's something that Coca-Cola or Proctor and Gamble just don't have going for them like RPG companies do. I've never met a person hounding me to try Crest toothpaste or Mello Yellow soft drink just because they like it. Autos are one market I've seen with similar enthusiasts, though; hobbyists who love Fords, or BMWs, will extoll their favorite car's virtues until you agree to test drive one. If an auto enthusiast feels taken care of, they'll work so hard to sell you on their favorite car, they act like they work for the company.
To me, that's why the OGL is as important as it is; without it, the die-hards just aren't coming back, and the changes away from several key 4E mechanics risk driving 4E enthusiasts just as well.