You may recall @Ben posted a little while ago regarding Gamemaster Audio, Peter (@Gamemaster_Audio) had kindly agreed to a 20% discount for GameDev.tv students.
Visiting the Gamemaster Audio website today I noticed that Peter is having a Christmas sale, you can now get an additional 5% off (that’s 25% for the mathematically challenged 
) until the 31 December.
So whether you celebrate Christmas or not, there’s a deal to be had during this time - big thanks Peter 
See also;
Anyone got the whole pack?
Thoughts?
Bought it this morning…
3.2Gb… it is still unpacking at the moment 
Seriously thinking about getting it too
I bought one of the smaller oacks before and that was very good, in hindsight I should have just gone for the big one. The smaller ones have a selection of sounds from the main one and are split into different themes as you have probably seen.
I couldnt bring myself to ask if it was possible to use the previous purchase as credit towards the big pack… hehe…
The website also has a link to a listing of all sound files contained within
I asked peter if he could multiply the chrismas discount and our coupon still waiting for his reply.
When you buy it, do they send you a code or validation number?
multiply!!! So, you want 20 * 25 percent discount? 500%!! You get the files and Peter gives you money… Good luck with that!
Once purchased you are redirected to a website (Sellfy) where you can download the .zip file from, additionally you receive an email with the link too.
Huge thanks to Rob for creating this thread! I was actually planning to post on these forums about the Christmas sale this week! Just to clarify, everyone on GameDev.tv gets a 20% discount all year round. However this month everything is 25% OFF. Joao, I’m sorry you can’t combine the promo codes.
Rob, I’m happy to do upgrade pricing for you. So I’ve gone ahead and refunded your purchase of the previous smaller sound pack. Enjoy the full collection
Lol, nice deal! Wouldnt it be? 
Those discounts multiplied would be 40% (0.8 * 0.75), well, there is no harm regarding asking for it, perhaps he is willing to give us 30% or 35%, who knows…
Hi Peter,
Thank you for your reply, sure, no problem! By the way, I meant no harm when I asked for it I tend to negotiate for everything as long as I can remember
I think your multiplying the percentage payable and not the discount!
Always worth asking Joao so no worries at all
Indeed, but at least commercially when I multiply two discounts, it is the payable percentage that will be multiplied. But I don’t know if in English it is the same thing since Its not my first language, Inside business administration (Portuguese, Brazil), if we “multiply” discounts we will do this way. Which word should I use instead in english?
If I multiply 20% for 25% it will be 5%
Hi Peter, that’s really kind of you, and unexpected, it really was my fault for not reading how the smaller packages were arranged in the first place… I was too eager!
Really appreciated though, thank you 
If we had two discounts; 20% and 5%, I would stack them to get 25%. Is that what you are referring to?
Hey noise, sorry for not being clear enough, my English is a bit limited (even more when is a specific topic such as this)
There are two ways of adding discounts that I know of, one is by stacking two percentages:
20% + 20% = 40%;
And the other is by multiplying the product of the discounts:
(1-20%)*(1-20%) = 64%
discount = 1 - 0.64 = 0.36
discount = 36%
The second one is the most commom case and will be used 90% of the times. it is the one I was referring to. But I don’t know if in English you would use another term rather than multiply the discounts, I think that the term for this would be “Compound Interest” while the other one I think that is called as “Simple Interest”.
/facepalm
What have I started?!
I see what you mean! I would call that chaining discounts.
Good to know, seems that saying just multiplying the discounts in English is quite vague, I’ll make sure to use Chaining discounts the next time! Thank you for that @noise!
I think it comes from the confusion of describing how your working out the chaining.
If you say you’re multiplying the discount it reads like multiplying the discount percentage 0.20 * 0.20 whereas your actually multiplying the actual sale price percentage 0.80 * 0.80. I don’t actually know the name for sale price percentage which is could be the possibility for the confusion. sale price percentage doesn’t seem right to describe the 80%