Re: Facebook effort for the opening line
Personally, I don't agree with using lines like that on Facebook with girls you don't know. That might be much more appropriate for dating sites and the like.
Approach girls on Facebook how you would in real life - have an excuse to talk to them, establish a false time constraint, etc. The fun part is the Number Close because you can say something along the lines of "I have some errands to run, but how about we move this lovely and not at all menacing conversation somewhere else?"
If she catches on, take some time to text her and keep the convo going from there, but don't make a big deal out of number closing. Perhaps the easiest thing after the approach
As for the line itself, it's perfect without the "random" part. Don't excuse yourself for being random. Use it on girls you know. That's what makes it gold.
A kiss close I came up with (and had success with) is asking her to marry me and then saying: "So...when do it get to kiss the bride?"
Always leave her better than you found her.