It's not a pageview, it's a widget view. Only the lowest-quality advertisers will pay for that quality and it won't be $1 CPMs. The OP could try putting a (non-compensated) ad on there and measure CTR and how many times the ad even is in the viewable pane (a lot of widgets are below the fold and are never even seen).
The SEO angle won't work-- JavaScript widgets aren't seen by spiders nowadays. The SEO hackers who did what you're referring to added links below the javascript in the code they provided. Downside of this is that if the OP wants to go this route, he can't retroactively add a link to these current users. Unless the link/anchor text relates to widget, Google will ban your ass. The guy who did the online dating thing did in fact get slapped HARD by Google. You can read about it here: http://www.seomoz.org/blog/widgetbait-gone-wild
You got your javascript widget and your noscript tag. You could even stick some regular HTML with a link (possibly an image instead of text) below those. Your users will copy-paste the widget along with your link.
This is a pretty strong SEO technique. You should be doing that already. You don't need to stick unrelated links there, just link back to your Twitter-themed site.
... Which gets him more unmonetized traffic. But yeah, of course he should be doing that.
Note: I wouldn't use the noscript tag. I'd either have a div that was replaced via javascript or a small/light chunk of html below the javascript. Pretty good chance of noscript tags getting dinged by Google given how they are being used.
The SEO angle won't work-- JavaScript widgets aren't seen by spiders nowadays. The SEO hackers who did what you're referring to added links below the javascript in the code they provided. Downside of this is that if the OP wants to go this route, he can't retroactively add a link to these current users. Unless the link/anchor text relates to widget, Google will ban your ass. The guy who did the online dating thing did in fact get slapped HARD by Google. You can read about it here: http://www.seomoz.org/blog/widgetbait-gone-wild