Not sure about the OP but I received my samples in 2016...and they were very generous samples.
1 250ml bottle and 2 60ml bottles, a pack of rolling papers, stickers, and a feed chart.
They've definitely been around longer than a yr and @ .06ml per gallon I'm VERY happy with the results.
No I don't work for Mammoth P (though I have done my fair share of research and testing)
Yes I have plenty of pics all over the site
And yes, I'll continue to buy this until something comparable comes along.
Mammoth P and Real Growers Recharge are the only two products OTS I use in my built soil so I figure its worth it for the very noticeable stalk strength and final bud size.
OP, Mammoth P should be strengthening your plants stalks and stems, hence the slight increase in yields. Got any full plant pics?