How long the disc media will stay on the market?

A lot of companies over the years say that memory cards will replace all the Disc Media technology on the market and no one will buy CD or DVD any more. As you can see, more and more formats just continuo to come out over the years. For example the Blue Ray is now one of the top technologies on the market that everyone talks about.
Many of my friends ask me all the time why I continue to work in the CD/DVD field. They are sure that this field in 1 or 2 more years will stop to exist. Every time that one of my friend asks me this question I explain him that the CD market will remain at list for the next 20 years. Of course their first face reaction is what the hell I am talking about but after I explain them my point of view they start to understand that I am right.

The problem with memory cards (Pen drives, USB Sticks, SD and etc) that they are very expansive comparing to CD/DVD. For example, a 4.7 GB DVD-R disc will cost you maybe $0.5 USD, but a 4 GB memory card will cost you at least $10 USD (a very simple one). So maybe for a consumer is nice to buy 1 memory stick and delete and copy all the time, buy what will happened when you will need 100 copies to give to your customers? You have 2 choices, 1st is to use 100 DVDs that will cost you around $50 USD. The other choice that you have is to use 100 memory sticks that will cost you $1000 USD. Which option you will use? More than that, let’s take big companies that need to duplicate there software more than 10,000 Pc, what do you think they will use? Of course they will choose the DVD option! It’s much cheaper then to buy 10,000 memory sticks! Just for the fun of it. 10,000 DVD will probably cost them around $5000 USD when 10,000 memory sticks will cost them around $100,000 or even more, so which one you think the companies will choose.

So in the end, the media technology will stay with us at list for 20 more years (if not more!) and the reason is very simple, cheap to buy and cheap to produce!