Just some historical observations ... and a bit of speculation ... about attitudes changing in our favor ...along the same lines of Demand for guns/accessories/ammo increases after these incidents.
Observation
As anti-gun people call for bans, demand increases among those desiring "pre-ban items" for either personal use or investment
Observation
ALSO, some non-gun people get guns (just like applications for licenses to own guns increase in Australia after burglaries) "while they can" in order to protect themselves, since reality/realization of what can occur set in... Obama, by talking about gun control, has sold more guns than any prior person in that office (not even Counting all that Holder sold illegally and Hillary sells legally to other Countries through the State Dept, even though that number increased drastically too)
Observation and a bit of speculation
Twitter account followers (as an informal poll)
Anti-gun promoter Tweeters- a couple have minor increases in followers; Several have fewer followers than they did.
Most anti-gun people lock/protect their accounts (Most all the anti-campus-carry ones did since Colorado passed Campus Carry last March upheld by the Supreme Court, and The Theater shooter drops out of college ..., probably avoiding a gun-free zone campus massacre; since he opted to choose a less-self-defense-friendly atmosphere so he'd have more chance to continue without dodging returned fire)
My Twitter account, mostly Pro-2A tweets, with logic and reasoning, many containing incidents and rational you guys post here, (often containing a link to a thread here,
which may help some "undecideds" understand better and increase forum readers)
has increased in followers to 1,740 followers as of this morning;
(EDIT and ...4 more just as I am writing this 
an increase of about 350 followers since the Aurora occurrence. (
Most anti-campus carry guys are down to about 300 to 400 followers now)
Though time is limited, I continue Tweeting for one purpose ... 2013 Texas Legislature ... last Session I had about 100-200 pro-campus carry followers while the Congressmen followed back AND TWEETED BACK TO the anti-campus carry tweeters who had 300-600 followers ... As they believed they represented a greater number/cross section of voters ..
Last year ... I saw one guy with 20,000 followers who E-mailed a US Senator and got no response to his E-mail Tweet about it ... and tweet a message to that Senator ... and he got a response the next day after mentioning what he'd tell 20,000 followers who vote... Mass Media isn't the only influencer ...
And ... My personal purchasing decisions are affected
I'm placing an order for more "over-10 round mags" for Glock 19 and 17 to use in my 26 and 19 perhaps another Glock 26, and had I more cash, I'd get an AR and AK, but last month's $700 exterminator bill and $700 car maintenance and $4,200 loan to brother and some expected medical tests expenses, sorta changed my cash balance/plans temporarily for a couple months.
I'll wait to get a DB8 Diamondback compensated 9mm I want (under 10 rounds) and a nifty small capacity pocket .45
My Parkerized PF9 is going up for sale I paid $356.14, plus a grip extension and a spare mag. Still in box, with lock and book etc, about 50 rounds through it worked with no hiccups with Critical Defense and Gold Dots.
Reason for sale: I just prefer my PT709 and don't need 2 8-round 9mms.
Probably won't bother listing it here in the sale section as I am far from most of you guys and don't want to mess with shipping; but If you are close to Lampasas, Marble Falls, Bertram, Burnet, Kingsland maybe Liberty Hill or Georgetown (I need to get over there one of these days).. I'll meet you. (Or, I might be in Lubbock or Pasadena in October or September) Oh, I'd take $300, or gimme an offer close to $300 (I couldda sworn I had another mag or 2 for it; if I do, I'd mail them to you later if you want; if I don't have others, then that's it, maybe it was the PT709 I had more for ... house is a mess right now with mags etc scattered)