I was thinking…

But seriously, using discounts on specific products is partly about shifting over-stocked items, partly to get a bit of fun going on to make the brand more widely known. It cannot ever be a significant quantity as its a business to make profits.
That 300 Elite giveaway is costing Anker (estimated) $2400. The member giveaway costing say $250. Anker’s turnover is $378M
I’d expect that no more than 1% of revenue would be associated with using social media to garner interest, so about $4M, of which they spend (counting names) about 10 people on social media which would be about $1M, funding specific events would be about $1M so likely only $2M to be spent on discounts and promotions. As a median of $20/item that is 100,000 items/pa or 280 items per day. That tallies with the order of scale of offers, how fast and many sell, e.g. 280 is not far off the 300 Elite giveaway.
Pure guesswork from typical commercial operations.