I have a few of those that my son plays with...I'm not even sure where he got them from! It must have been Grandpa. 
I dont have any kids, but I definitely want a few!
I think I got them from the toy isle at the Grocery stow.
I’ve already bought about a 1000 packs of these over the last couple of years for my kids school as we sell them at school discos and firework events that we do at the school. First year we had them they were a big hit with the Adults too for Christmas parties. They are way over priced on your link though I pay a fraction of that
Amazon 10 packs for $5 is closer to wholesale price.
I'd say 3 in 10 don't work well.
Usually end up buying boxes of 80, and give them out at parties... they are a big hit. Prices have gone up lately on all of this stuff unfortunately.
These are surprsingly bright when it comes to blinking;
And don't forget the glow sticks;
http://www.amazon.com/gp/product/B00550LX1U/ref=ox_ya_os_product_refresh_T1
And lastly, the gloves: http://www.amazon.com/Raver-Blacked-Gloves-Colors-Light/dp/B00BSB21IO/ref=sr_1_1?ie=UTF8&qid=1414699487&sr=8-1&keywords=led+gloves
There are different versions out there, for all price ranges, so I suggest going with those cheapest versions first... you won't be too upset when they break. Also grab some spare batteries and kids will be all set.
my wife bought a bag full of them off amazon, they are fun little toys