I've had a lot of fun, a lot of frustration, and gained a whole lot of knowledge. You'd have to say that as an investment this has failed completely, but as a learning experience it has been worth it. Rather than speculating, I put up the cash to find out for sure whether this was worth doing. I haven't solicited any donations -- only technical assistance running my rig.
Funnily enough, I really haven't spent my bitcoins on anything besides mining hardware! I don't plan to cash out to fiat, but rather to save the BTC for future online services.
Unfortunately, the sales pitch from sellers of mining hardware and cloud mining has emphasized words like investment and profit. That's how they've been able to make their profit. Those of us who have tried it out now know otherwise. The real investment here is that you took the chance to learn about cryptocurrency while it is still in it's infancy. You are an early adopter, and have the opportunity to make some moves in this early stage that could lead to a payoff at a later date. We haven't figured out what that groundbreaking move will be, time will tell.
I started off with a 30 GH year contract from a seller on ebay. Then got into mining with a rig made of USB technobit HEX16A2 miners (also from ebay), starting with a pair of miners early in March 2014. Over the first month I worked my way up to a total of 6 miners (about 130 GH or slightly more assuming ideal conditions). I also had some trouble with the software that came with it. The USB connection was flakey and would periodically drop out, often while I was away from home, leading to lost mining productivity. I would need to come back often to reset it. A user on here helped me make the transition to a more stable cgminer version for technobit miners. Once I got it properly configured, it has run rock solid, with hardly any hiccups. About 125 GH on average. I figure that the weekly power costs is about $8, so I will obviously be shutting it off at some point within the next couple months. At the peak, I was seeing a 0.01 BTC payout per day. Now it is down to a bit longer than every other day. Sometime soon it will be down to every third day.
The total cost of the miners was around $970. Add 13% GST, since I imported them from the States to Canada. So now up to $1096. I also ordered special adapters and 4 different computer power supplies. I blew the first two, which were cheap. Then I opted for 2 good ones. Then I bought a new computer so that I could dedicate my old laptop to mining. So basically completely forget about any fiat for bitcoin and back to fiat return on investment.
I think I am now done with reinvesting in mining. At first I was excited to be buying and adding mining equipment. Then I noticed that the ebay seller was dropping the price significantly. The very last miner I bought was half the price of the first one. Something was up. I had to do some homework to figure out what was going on with the mining difficulty and the ROI, and make sure to not get carried away.
After 3 months, as of today I have just reached 0.6 BTC according to my BTC Guild dashboard. I have reinvested the majority of that into PB mining, with a current contract of 150 GH. My multibit wallet has received close to $900 worth of bitcoin from a variety of sources since I first downloaded it last September. Now I think I am done with reinvesting in hashing power. I am instead trying to spend my weekly earnings on items that I will enjoy, including coffee. Whatever gourmet treats I can find on amazon with free shipping, such as handmade pasta sauces. The next bitcoin I will get will come from a fiat exchange.