That's not what the authors who hang out on wattpad say.
It varies, but my fan base is largely 'price inelastic', meaning they're less impacted by price. Many independent book sellers take the opposite tack, marking their books as low as possible (though the optimal price for ebooks seems to be $2.99, rather than free), but for the few new readers I pick up thru 'free' giveaways, I don't garner many additional book purchasers, which I interpret as 'freebies don't buy'.
One of my business models in past years is to continually attract new fans, because each stands to purchase multiple books, but I've done better offering books at a 75 or 80% discount, rather than offering them for free, as it weeds out those uninterested in purchasing.
That said, I also haven't garnered any 'library sales'. In years past, authors typically gave libraries free books in hopes of garnering sales. Not only have libraries refused to order any of my books (only one to date), but the few local libraries I've given free copies, as a local author, promptly shipped them off to the state capital regional library, rather than keeping them locally where people would be interested in reading my works.
I suppose the 'free' benefit depends upon the companion prices. A free book is probably more likely to produce sales of a $2.99 book, rather than a $5.99 book, but since my sales are inelastic, I now focus on making my books as 'professional' as I can by adding value (grapics, design, previews of other books, cast lists, etc.) to justify my higher prices.
In terms of my print books, my sales jumped when I went from $5.99 to $7.99, $9.99 and eventually $14.99. Print books still aren't a major factor for me, but it reflects certain trends. Raising prices on my ebooks cost me a few sales, but it's more than recaptured by the return on investment. Since I sell to fewer readers, and most readers are paying me when they can read my material for free, I figured 'why give someone else (namely Amazon) my money?'. So instead, I try to make my published books more interesting than the stories on SOL.