I only skimmed the article so might've missed this, but you'd hope they'd work affiliate links in there on products and potentially split revenue with users. Even then, it's a pretty big step to hand over a bunch of your logins just to scrape a couple of cents from your handful of followers.

Once I ran a list of my ideas past a venture capitalist. He liked a good number of them, but for a few of them, he simply said "What problem does this solve?" and within a few seconds I'd realised that those ideas were likely duds or, at best, up-hill battles.

I think it's a good question to ask early in any idea brainstorming.

Store cards and rewards cards are a similar goldmine of information, but they provide quite strong incentives - frequent flyer points, discounts, etc. Not to mention, less risk.

What I've been thinking could work for that is a list of "things I've got my eye on". Maybe a digital SLR in the $1-2k range, a better iPhone deal, flights from AU to the US, a fridge, etc. And then the clever friends could act as 'buying agents' to help source the best deal and take a cut along the way. The original deal-seekers could list a target price they've discovered so far and have the agents look to beat it.

Agent offers could be on behalf of friends or friends of friends or 'approved accounts' to deter spammers.

All the original seeker wants is the best deal. The clever friend would be happy to help and split the affiliate cut with the host site.

With Blippy, I think notification of post-sale is mostly helping the followers (e.g., someone like you just wanting to buy what your friends have bought) and not people in the research or purchasing phase without a friend to follow.

- building profile and spreading word about own business/products is harder without it

- longer-format writing (blogging) takes too long and can be too much of a commitment

- Facebook is a walled-garden and (at the time?) wasn't as suited to businesses