Yes, that is correct. Marvel Comics (and Disney by way of proxy) is giving away free digital copies of over 700 number 1 issues from the past 50 years!
This was just announced at SXSW (that South By Southwest for those of you not in the know!) and unfortunately it crashed the servers at Comixology!
Keep on trying if you can’t get through. You have until Tuesday, March 12 to grab as many as you can!