I've played a metric shit-tonne of game, and only maybe a dozen, two dozen LPs. Why? Cause a good LP, adds to the experience. Freemans Mind, is an excellent example, as well as Princess Maker 2. In the first, as if Gordon is a egomaniacal sociopath. The second, as if the Narrator is Gendo Ikari. Both added to the game, a unique twist and slant, and ideas - Gordon thinking he stumbled into a Lovecraft story, and Gendo buying Big Boob Pills .... for himself.
If it had simply been watching some idiot play the game, with nothing added, and spoiling all the surprises, I'd remember them far less. Planescape Torment, or Knights of the Old Republic, would probably have not been bought if I got the reveals and scenes posted as simple youtube clips. I've played Succession games of DF with mates, again because it added so much, as did their narratives about it (and also sighing sadly at all the 'decisions' my forebears made, and wondering what the hell they were thinking).
So, in short, a LP is like gamer TV, with MST3K trappings - it loves the game, and expands it. If it was just a camera recording the play, with occasional grunts and "That's what she said!" at the 'wittiest' moments, then that's just stealing any enthusiasm I had for the product away. I have purchased games from good LPS, I plan on doing an LP of a recently released game in a few months, simply so as not to tread on their toes, and I am happy to say I pay for things I value, and value the things I spend time on enough, to spend money on. It's a simple, nicely circular train of logic.
INdies need love, word of mouth and to be treated fairly. AAA, well. Most of them are dogshit anyway, and the masses can do what they like to them. Not exactly going to surprise and shock, showcasing the latest COD, Madden, Halo, whatever.
My humble opinion, as a gamer with eclectic and ranging tastes.