No it's a fluke. I didn't post the linkback. I think what happens is that since I publish the most recent forum posts in the sidebar of my blog, then it sometimes links back sometimes from one specific blog post that isn't even related. I'm not aware of any connection between SureHits and eTrade.
I did mean to comment on this post eventually though. Over the past couple years I've seen affiliates search for a stock market related affiliate program and to my knowledge no one ever found one. So it makes me think affiliate programs may not be allowed in that market sector. I've read that it's against the medical code of conduct (or something like that) for Drs. to pay for referrals, so possibly there is a rule against it for brokerages.
There are CC and savings affiliate programs but no brokerages that I know of. The only program I'm aware of that deals with stocks, besides investing courses and stuff is OneShare -
Oneshare.com - Affiliate Program. Probably not what you are looking for.