user24433: I have tried one of the hashpower selling/buying website (nicehash) to buy hashpower. I have connected my order to a pool where I had one worker. 
However, despite all the advertisements, I could not make a profit! I do not know what to watch to know whether my order is profitable or not? 
And what makes the profit at all? Is it the fact that the hashpower I buy will become more hashpower if I mine in a pool (I observed that sometimes that is the case, but not for the whole lifetime of the order)?
Thank you!

user5292: The profit is the lesson: you got scammed. 

user9382: I use this analogy for cloud mining: 

If you had a money printing machine would you rent it out or use it yourself? 

Cloud mining -no matter how you consider it- makes no sense financially. If the company is making a loss, they'll be out of business, if they're making a profit, why aren't they making that profit directly? 

user14920: The short answer is cloud-hashing is not profitable as you might expect. You can still generate profit but its value is minuscule compared to the investment. To concretely answer this question, I'm going to share with you a model I developed to calculate profit from the cloud-hasing service (bit-miner.com).
Profit Model

Google Sheets Link if you want to fiddle with the numbers.
The Investment
I bought a total of 30 shares for an investment value of 322$ (payment charges included) for 9.90$ a share. The service distributes dividends twice per month for  the value of ~0.00128193 BTC per share.
The Math
Given the investment above, this service will put in my balance a total of ~0.0807714 BTC per month. Assuming the BTC/USD exchange rate is fixed at 255USD this means I will generate a revenue (not profit) of 20.59USD per month.
Now, let's assume my investment will span between February 2015 and December 2016, I will break even on June 2016 and make profit of the value of 17.35USD if the BTC/USD exchange rate is still fixed at 255USD.
There are 3 ways this situation could evolve (from today the investment date):

Best Case Scenario: The BTC/USD rate will increase and I will break even sooner and actually make more profit. For this profit to be substantial the rate should double if not triple (highly unlikely).

Normal Case: If the BTC/USD rate is still the same, by the end of this investment period, I would have generated 1.815 BTC for a cost of 322USD and a profit of ~140USD (exch. rate BTC/USD 255USD)

Worse Case: The BTC/USD rate will drop and eventually I will be at a loss. Or, the service owners will decide it is not profitable for them anymore (given the increase of the difficulty factor) and they will sell the hardware and distribute the returns based on the number of shares owned. The catch is that this hardware deprecates quickly and everyone will be at a loss by the time the owners decide to sell.


Before concluding, it's important to note that the Dividends per Share value is likely to decrease with time as it is inversely proportional to the Bitcoin Difficulty value.
All in all, if you want to experiment and get involved in the bitcoin scene and have a few hundred dollars you want to spend here or there, go for it. If not, find other ways to procure/invest in bitcoins that are cheaper and faster.
Disclaimer: I'm not an economist or a financier, so please forgive any misuse of technical jargon.

Edit: I edited the Google spreadsheet to take into consideration the mining difficulty. The impact is not large, but it makes the projections more accurate.*


24433: <p>I have tried one of the hashpower selling/buying website (<code>nicehash</code>) to buy hashpower. I have connected my order to a pool where I had one worker. 
However, despite all the advertisements, I could not make a profit! I do not know what to watch to know whether my order is profitable or not? </p>

<p>And what makes the profit at all? Is it the fact that the hashpower I buy will become more hashpower if I mine in a pool (I observed that sometimes that is the case, but not for the whole lifetime of the order)?</p>

<p>Thank you!</p>
 5292: <p>The profit is the lesson: you got scammed. </p>
 9382: <p>I use this analogy for cloud mining: </p>

<blockquote>
  <p>If you had a money printing machine would you rent it out or use it yourself? </p>
</blockquote>

<p>Cloud mining -no matter how you consider it- makes no sense financially. If the company is making a loss, they'll be out of business, if they're making a profit, why aren't they making that profit directly? </p>
 14920: <p>The short answer is cloud-hashing is not profitable as you might expect. You can still generate profit but its value is minuscule compared to the investment. To concretely answer this question, I'm going to share with you a model I developed to calculate profit from the cloud-hasing service (bit-miner.com).</p>
<h1>Profit Model</h1>
<p><img src="https://i.stack.imgur.com/6yXsX.png" alt="Cloud Mining Profit Calculator" /></p>
<p><a href="https://docs.google.com/spreadsheets/d/1kae0A23E4csD-qC-WLtChjVUxudki18Irdkgqc7BsEM/edit?usp=sharing" rel="nofollow noreferrer">Google Sheets Link</a> if you want to fiddle with the numbers.</p>
<h2>The Investment</h2>
<p>I bought a total of <strong>30 shares</strong> for an investment value of <strong>322$</strong> (payment charges included) for <strong>9.90$ a share</strong>. The service distributes <strong>dividends</strong> twice per month for  the value of <strong>~0.00128193 BTC</strong> per share.</p>
<h2>The Math</h2>
<p>Given the investment above, this service will put in my balance a total of <strong>~0.0807714 BTC</strong> per month. Assuming the BTC/USD exchange rate is fixed at <strong>255USD</strong> this means I will generate a revenue (not profit) of <strong>20.59USD per month</strong>.</p>
<p>Now, let's assume my investment will span between February 2015 and December 2016, I will break even on <strong>June 2016</strong> and make <strong>profit</strong> of the value of <strong>17.35USD</strong> if the BTC/USD exchange rate is still fixed at 255USD.</p>
<p>There are 3 ways this situation could evolve (from today the investment date):</p>
<ol>
<li><p><strong>Best Case Scenario:</strong> The BTC/USD rate will increase and I will break even sooner and actually make more profit. For this profit to be substantial the rate should double if not triple (highly unlikely).</p>
</li>
<li><p><strong>Normal Case:</strong> If the BTC/USD rate is still the same, by the end of this investment period, I would have generated <strong>1.815 BTC</strong> for a cost of <strong>322USD</strong> and a profit of <strong>~140USD (exch. rate BTC/USD 255USD)</strong></p>
</li>
<li><p><strong>Worse Case:</strong> The BTC/USD rate will drop and eventually I will be at a loss. Or, the service owners will decide it is not profitable for them anymore (given the increase of the difficulty factor) and they will sell the hardware and distribute the returns based on the number of shares owned. The catch is that this hardware deprecates quickly and everyone will be at a loss by the time the owners decide to sell.</p>
</li>
</ol>
<p>Before concluding, it's important to note that the Dividends per Share value is likely to decrease with time as it is inversely proportional to the <a href="https://bitcoin.stackexchange.com/questions/23099/what-does-the-mining-difficulty-number-really-mean">Bitcoin Difficulty</a> value.</p>
<p>All in all, if you want to experiment and get involved in the bitcoin scene and have a few hundred dollars you want to spend here or there, go for it. If not, find other ways to procure/invest in bitcoins that are cheaper and faster.</p>
<p><em>Disclaimer: I'm not an economist or a financier, so please forgive any misuse of technical jargon.</em></p>
<ul>
<li><strong>Edit</strong>: I edited the Google spreadsheet to take into consideration the mining difficulty. The impact is not large, but it makes the projections more accurate.*</li>
</ul>
