As the blog author I thank the OP for drawing members attention to it.
Terry wrote:
"
No mention of UK dealers cancelling their contracts with Royal Mail because they can't sell modern GB stamps resulting in devaluation of their stock. Or of dealers using their stocks of modern GB stamps for postage to offset their outlay. Or of UK collectors giving up on collecting GB stamps because of the excessive numbers of, generally poorly designed, spurious issues each year in various alternative guises intended to lure the completist collectors. "
The main purpose of the blogpost was to inform UK readers and collectors of GB stamps of the difference in approach between the two organisations. I have no knowledge about the USPS' contractual arrangements with any dealers for standing orders of new issues - which is why I didn't make any comparison - but from what I understand from US-based dealers and collectors, both are cutting back on which new issues they collect and have been (as they have been here) for a decade or more.
But to confirm what you wrote. Rushstamps and the Edinburgh Stamp Shop are two of the higher profile companies that have stopped dealing in new issues. So have we at Norvic because Royal Mail make it easy to buy collectibles on
ebay and on their own webshop. What they don't do is provide a philatelic service for specialist Machin collectors, and they have been happy for the Trade to fill that gap. However, there were murmurings at the Trade Briefing in September that they are reviewing what they make available to collectors of stamps other than 'collectable pictorials'.
Much of the discount postage being used (or sold) by dealers comes from collectors liquidating their holdings. But as you say, we are also using the stamps that we bought but which proved less saleable. I have stocks of Olympic and Paralympic Gold Medal Winners stamps which sold very well at the time, but which nobody wants to buy now. (Look out for special offers soon at shop.norphil.co.uk

)
@wt1 - US panes have to be sold complete because of the interlocking perforations, something that has never been done here - our self-adhesive stamps have perforations that look like normal stamps. And the terms of our contract with RM allow us to return up to 20% in value of our purchases p.a. if we over order.
End note: despite the opinions of traditional collectors on the state of the UK market and of stamp products and design in general, people continue to buy not only stamps but other 'collectables' which is why the postal authorities keep producing them. They just don't cater for the completist collector any more, but to niches.