But what it's starting to annoy me are the widgets. While I'm aware it's a very nice source of traffic, this is getting out of hand and the reason is simple: the iframes.
iframes are one of the slowest elements in HTML (in my personal experience) and while having one or two loading into your site, is not really a bad thing, it really adds up when you load 10 or more
Just check Seth Godin's main page [http://sethgodin.typepad.com/], try to scroll down and look how it blocks your browser for a few seconds.
I think that's a very bad experience.
When I started using Adblock, the web started loading a LOT faster without all the ads (loaded with an iframe).
And now, I'm starting to block these widgets on a site basis (starting with Seth's blog, via adblock), but I'm sure pretty soon I'll have to block them all.
I think this is one of the main reasons Google Reader sucks so much: the Plus One button. It has no keyboard shortcut, it's slow to load, it freezes up the browser-- I had to create a Greasemonkey script to block them all and now the experience is a little bit better. Let me know if you want me to upload this GM user script.
What I'm trying to say is that if you're going to build a professional website/webapp in 2012, you'll have to consider mobile. And if it freezes my browser for a few seconds, imagine what would it be for my smartphone browser.
I think here's a good idea for a startup: widgets without all the lag (and privacy concerns).
Loads and runs lightning fast for me. Of course, I'm using RequestPolicy, so I don't have to load all of the third party crap that he includes from addme.com, google.com, sethgodin.com, facebook.com, quantserve.com, youtube.com, feedburner.com and scorecardresearch.com
You're handing over control of your user base to a third party.
Some people don't like Disqus tracking them all over the web.