Popup window within a .js file

How would this impact SEO optimization

[Bradley]

Pretty straightforward issue:
Our site gets substantial traffic to the overall site, but the ultimate goal of our site is to have the visitor fill out our request form....Our conversion rate is around 1%

One way to dramatically increase this conversion rate will be to implement a small popup window upon the visitor's initial visit to the site.

Because I don't want to have to modify 900+ pages on our site for the popup code, I am thinking about placing the popup window code within a .js file. This js file is already being executed on every page.

Of course I want to make sure this does not "upset" the major spiders including Google.... If this popup code were placed within a .js file, would google and other spiders be able to recognize this code?

I've read through past posts that state that the spiders do not read .js files, but I want to make sure that is still true today.

I'm not trying to hide anything per say, but rather I just like to keep my pages as clean as possible. I think this would be a great solution to my needs, but want to make sure I won't get penalized by Google and the other spidering search engines.

[buckworks]

This is not quite the same thing, but I use external .js files for search boxes and pull-down menus that appear on hundreds of pages. Google doesn't seem to mind external .js files for those, so I don't see why putting a popup window in an external .js would cause problems.

I've recently been testing an exit popup on a couple of pages for promoting a specialized newsletter, and there's a huge difference in the number of signups compared to just having a static signup box on the page. For me the difference has been at least five-fold, so I'd say it's definitely worth some experimenting.

[tedster]

I've never seen a spider call for a .js file. I've heard some random reports here and there, but it never turns out to be a standard spider crawl, at least so far.

But still, the pop-up isn't spammy, right? So even if spiders do develop an appetite for .js files, I can't see the harm.

Please report back on whether this really does increase your conversion rate, as you hope. Much curiosity here.