How good can a free game be?

PoE looks amazing, I gotta say. It looks how most people wanted D3 to look. But we don't have to buy it? And it's been in development since 2006? Really? Almost sounds too good to be true.

PoE is developed only by a few programmers and that means that they need more time to create a good game. Game developers like blizzard have more than 100 programmers and that means a higher cost factor. These costs do not arise in poe (not sooo much). thats why they can bring it out for free. there will be a "shop" where you can buy some extra stuff "Completely free to download and play. Supported by ethical microtransactions" .. and yes its true;) we will see what the future bring to Path of Exile and the GGG Team. i wish them all the best

There is some more detailed explanation here... http://www.pathofexile.com/news/2010-11-29/dev-diary4