Vinyl’s rebound has lasted long enough to raise questions about how much further it can go. The pace of growth remains remarkable. After bottoming out at less than 1 million copies in 2005, sales of new vinyl albums soared to 9.2 million copies last year, according to Nielsen Music. And yet vinyl still makes up only a small niche: 4.5% of the overall U.S. album market last year, according to the Recording Industry Association Of America. Prices, meanwhile, have been climbing: The average vinyl LP grossed $23.84 last year in current dollars, based on RIAA data, up almost 40% from an inflation-adjusted $17.20 in 2005. Let’s see: rapid sales increases. Rising prices. All for a product geared at a relatively small segment of consumers who will pay for a commodity, music, that’s generally available for less — or even, legally, for free — in other formats. It doesn’t take an economics whiz to see the makings of a potential market bubble. If it pops, some indie labels, stores, and artists who helped foster the format during in its lean years worry they could be collateral damage.

I mostly purchase vinyl records to a) financially support small time artists I enjoy and b) discover new artists and music. How about you?