How flipping websites is like the stock market
flippingsage.com
flippingsage.com
You need to take in to account the party that receives what you've created and you have to make sure that that party has your users best interests at heart. If not you'll end up with some money in your pocket but a tarnished reputation.
And if you buy websites purely speculative you have to ask yourself if there isn't a market better suited to that kind of behaviour.
To assume that only blogs or services are bought and sold is a mistake. However it is true that finding a proper buyer is always a concern. Buying and selling websites can be more involved than buying and selling stock for sure.
If you are a computer geek who knows websites better than the stock market, then buying them speculatively could be more interesting than you give it credit.