Quite a lot of professionally published work isn't terribly good, so it's not as if professional publishers are effective gatekeepers. But their output sells (to the extent that it does) because they have the distribution networks needed to get books into bookshops, and the PR network needed to create a buzz.

So Lulu is not the answer. Self-publishing is a waste of time unless you have some way to do effective promotion. And in fact, people trust bookshops to offer them something which is better than average. It's almost impossible to create that experience on Lulu.

The people who do well out of self-publishing are the scammish 'get rich quick' '100 top seduction secrets' 'essential ways to wipe out bad credit' artists who sell PDFs direct from a website. There's usually a SPECIAL LOW PRICE TODAY ONLY!!!! tag somewhere near the bottom, the hardest of hard sell further up, and regular spam reminders afterwards.

It's rather vile and seedy content-wise, but it's much better at making money for the people who do it than publishing on Lulu. The overheads are much lower - the hosting cost of a few PDFs and a website is negligible - and with clever Google-fixing people come to the site, so a PR operation is unnecessary.

Obviously this model wouldn't work for ET-ish books.

ET-ish books could only be sold with an established name - ET Think Lab, etc.

Once the name is recognised, book sales become a natural development.