Especially since this is such a low hurdle for US applicants to clear (this is not always the case for applicants from other countries,) if you can't provide enough real world examples to clear it, it's a real problem. In the entire time I've been reading this site, I think I saw only one case where the visa was rejected cause the ECO didn't think the relationship was genuine.
Yeah, it's definitely good to have those RL things, and it doesn't hurt to sprinkle a couple of inbox screenshots and such throughout, as long as you have those things like phone bills and letters and photos *for sure*. In my case I'm collecting some phone bills even though I'm applying for a spousal visa, since it's incredibly hard for me to fake them since the call logs are printed on the back of my bill >.> So if you do that, and take some pictures together when you're over there, I think it'll be okay. Like Mort said (and other people have said it as well) we're incredibly lucky to be applying from the US as American citizens, since sometimes we don't have to show as much to prove a point as we would be if we were from some other part of the world.
I just don't think the ECO wants thousands of pages of logs off the internet--if I were to provide mine, they'd reject me just out of frustration since we've been sending emails and using MSN multiple times a day for 3 years
![Smiley :)](https://www.talk.uk-yankee.com/Smileys/classic/smiley.gif)
And like what's been pointed out, those are easier to fake than a phone bill or a hand-written letter.