I did a search for market data to see how the snuff market was doing and the findings are meager and contradictory. One study about the German market states that:

Volume sales of smokeless tobacco are predicted to see a fairly sharp decline over 2014-2019 because very few young consumers are buying these products on a regular basis.

http://www.euromonitor.com/smokeless-tobacco-in-germany/report

However another about the USA market says:

Nationwide, cigarette smoking control has been very successful and we have experienced a steady decline, but that success is being offset by the increased use of smokeless tobacco products, especially by youth.

New data shows spike in smokeless tobacco sales

Anyone has a clue or insider knowledge about the real trends? Sales volume? I guess the key market is the UK considering all the mills that are located there.

Freak data: GletscherPrise accounts for 48% of the sales in Germany.

Smokeless tobacco in America does not mean snuff, it means chaw (chewing tobacco) mostly in the forms of pouches (Skoal, Grizzly, etc.) and to a lesser extent leaves (Redman, Beechnut, etc.)

I don’t know where the top snuff markets are and I don’t know that having the mills located in the UK is an indication of where the main market is so much as where it historically started and remained for a long time. I think there are probably some significants markets where the supply is almost all from domestic sources (India and other Asian countries) and most of it is not exported at all.

The only people who really know are likely the people making and selling the snuff.

Roderick at Toque has managed a successful start-up in the last few years, so that would suggest that there is some potential for growth. I suspect it is to some extent a regional thing in Britain - since moving to Yorkshire I have found more b&m shops selling snuff, and more recognition when I produce a snuff box.