Sell copies of the game? Well, "personal use" includes giving copies away to everyone, so unless you're selling that first copy for a million bucks, you're going to lose your shirt. (Please don't give me that tired fucking bullshit about "well don't release it until people donate the amount you want," it sounds great if you discount that nobody will actually donate in significant numbers.)
This is an interesting theory. Given that the number of desktops running Linux is something around 2% (according to the marketing I've read) of all PCs in the wild, what if, after recouping production costs for the Windows/Mac/proprietary version, an LGPL client was released into the wild *and* the ability to purchase a valid, legal, interoperable license to run the software on Linux by:
- buying the boxed/published Windows/Mac/proprietary client and run the free LGPL client
- buying an official 'support license' using digital download of the LGPL client through the production/publisher's official website
There simply are not enough Linux clients to honestly regard piracy of an LGPL client as a threat to sales and yet this would be exactly the reason used to justify not releasing a Linux client or even a legal license of interoperability. Not the dollars/cents of goodwill and possible community interest and publicity it would generate, but the possibility of piracy and, if necessary, also discussing the doomed endgame of LGPL wrangling among the original publishers and forked projects. Isn't it okay that forked projects exist if the game already made money in the process? I mean, if we make the LGPL release contingent on the sales/profitability of other clients, there can be no loss, really. It's acknowledging a small enthusiast market and nurturing it as a wellspring of ideas instead of a threat to revenue streams.
Advertisements in the game to recoup your investment? Well, they have the code, so bye-bye ads and bye-bye revenue.
What's the alternative? I use AdBlock Plus judiciously and if I perceive a site to be 'peddling trash' I exercise my right to ignore their advertisements. Games don't go away, even when the companies and ad-agencies go bankrupt. What's the point? One bad game can ruin a company's reputation forever with a customer. There are too many options to expect a second chance using these methods and foisting (unprofitable, non-opt-in, non-opt-outtable, invasive) advertisements on the game reduces your market to the lowest common denominator of those who will accept them. The people who will not accept them know how to circumvent, avoid or boycott them, if necessary. Why do you care if people opt-out of the ad program they have no intention of validating anyway? They are just trying to enjoy the game and you're removing the acceptable terms of a sale, essentially counting the beans you collect from advertisers instead of placing a cent of value on your customers. Is it a financing problem? Do true fans need to tithe for something they've already purchased? I would still prefer to pay for the choice. How does removing choice benefit the relationship between publisher and customer when there is a precedent of something better?
MMO? All your code's out there, enjoy those free-to-play ad-free private servers killing what little market share you can scrape up.
There's something to be said for an officially sanctioned server as far as revenue models, but I don't think there's a silver bullet here. I don't play any big-name MMOs because I've had too many bad experiences in the past with the companies that run them...from EQ to SWG. If clients can take an active part in testing/tweaking and balancing a time-tested and weathered game experience, publishers would benefit from the ideas and mutual interests of their audience. The way you reference the use of the LGPL it is constraining development and blurring vision when its proper use empowers diversity and strengthens the underlying foundation. I think aside from the One-MMO-To-Rule-Them-All revenue model, MMOs don't work too well because they require a larger investment than the average game and a less guaranteed payoff for the player that they will truly enjoy the experience after grinding through whatever it is they will need to grind through.
I can buy the argument, though I disagree heartily with it, that the GPL is useful for low-level tools--operating systems, userlands, etcetera. "Information freedom" is the fastest way to killing the software industries that many people derive a lot of enjoyment from, though, and it's not like you'll be getting Half-Life 2 out of an open source project any time soon.
I don't pretend to believe using the LGPL is the best way to publish games, but I think at its root the LGPL has a place in the software lifecycle. If you interpret video games as art, when they are treated as nothing more than a thing to be constantly recycled and re-released for profit with expansions of new content that ignore already existing bugs, it really cheapens the experience of the audience. A game which achieves an LGPL-level of appreciation can serve as a monument and a constant check on the quality, honor and respect that exist between developers and clients in a healthy gaming community. It's not something you can point to on the bottom line, but for some odd reason the companies that embrace the philosophy of the LGPL in the right places have been very successful in building additional revenue streams.
That philosophy is pretty clearly missing from the vast majority of games released in the past decade - most publishers treat their customers like filthy criminals and most of the customers prefer to be locked up in a console because it's easier. Bugs are there so you don't get too much of an attachment to the game because the sequel will be even more juiced-up (eye candy only) and possibly more boring, even if it does, in fact, fix the friggin' bugs! Ultimately, developers have been validating investor/management assumptions that the sales cycle which fuels developer salaries is more important than the product which is ultimately developed. It's easy to be an ideologue when you're not trying to earn a paycheck, but where do developers draw the line? It doesn't pay to be dogmatic, but the lack of LGPL releases for some of the 'Best Of' category classic games has reduced the overall quality of what's considered 'releasable' and what 'goes gold' and what gets patched these days. The larger trend is that virtual publishing monopolies have removed healthy competition while enabling anti-consumer corporate polices in a lot of the PC gaming market (as predicted by RMS, incidentally).