If you want to use the service of figuring out what RAM you need, the very least you could do is buy the RAM from there. Even if it's 10-15% or so more I'll buy from crucial every time because of this service they have for figuring out what RAM you need.
I pick up a lot of stuff from newegg as well but I guess I'll make sure to buy all my RAM from crucial. I, personally, would prefer them stay in business and everyone who uses their services but then does not buy from them is only looking short term. If they don't sell stuff, they don't stay in business so their service you're using won't be there tomorrow.