How profitable is mining with a ~1GH/s miner? I'm very new to bitcoin mining, so I just tried it out on my mac using MinerGate. I made about 0.000028 XMR in 7 minutes running at 200H/s, equating to $0.0008. I figured that at that rate of money flow, I could make around $9.7/sec with just a 1GH/s speed. This does not seem very possible at all. So where's the poop?
Minergate is not by any means an effecient way to mine alt-coins. If you want to mine Monero XMR, you need to download either the source; and compile a GPU Miner, and configure it to mine off one of the many pools; and do the same for a CPU Miner; that plays nice with your GPU miner. 

Claymore's GPU and CPU miner are widely adopted and used, I am not sure if they work on Macs however. 

You can visit the bitcointalk.org thread for Monero; and get all the information you need on the OP Thread Post including links to miners; pools, exchanges, etc. 

But in closing; XMR is trading very high right now. I mined XMR two years ago and accumulated a lot of coins... this was when BTC was at 400-600 and XMR was 1/15th the current price. Across my systems; I was mining 10-20 XMR a day. But that was 2 years ago and difficulty is drastically higher now. 

HERE IS A LINK TO CPU / GPU BENCHMARKS FOR MINING CRYPTONIGHT ALGORITHM COINS

http://monerobenchmarks.info/

HERE IS A LINK TO THE THREAD ON BITCOINTALK WHERE YOU CAN GET STARTED

https://bitcointalk.org/index.php?topic=583449.0

In closing, you may want to look at AEON, which uses a forked version of Cryptonight, called Cryptonight-Light. It hashes at much higher rates. The coin seems to be in a bit of an unstable state development wise; issues with the new wallet release; etc, but in my experience mining the most profitable coin - at the moment - is not always the best strategy. 

The key is finding the lower difficulty coins that you can mine now at a loss; that will 10x or 20x in value 12 months ahead. Finding these coins is the hard part; but that's where the money is.