The amount of profit your company makes isn't what matters, the amount of profit Ares thinks you're making them lose is what matters. As long as they maintain their current clients, and they get to feel like they'll keep on doing so, they don't care about you. But the instant someone doesn't renew a Knight Errant contract because you're undercutting their prices? As soon as you make a headline for a daring rescue mission and they see the media giving you free advertising? Once word hits them from their CI's that you're doing runs against them to make them look bad and gobble up their clients?
Then.
Then is when the shit hits the fan.
True, but that doesn't mean they automatically do anything beyond "trim the fat" of their own operations. Sometimes the best way to maintain a lead is to see what your competators are doing better, and improve yourself.
Lots of factors go (or, SHOULD GO) into calling for a shadowrun. True, bottom line is going to be the biggest factor but it's not the only one. In the example above of hiding runs under the umbrella of "security consultations", let's assume a tidy posting of a profit of $1 million. (note: if as a runner team, you are making this level of cash... Well, retire while you got most of your bodily functions!!)
To a megacorp, $1 million doesn't even pay the weekly salaries to the minimum wage earners... It's small time change. Since all your work (mostly) is illegal and laundered under your front, the megas aren't losing anything. Some corp hacker, sleazing his way through the taxation office might find the info and pass it along up the chain where it gets filtered into the file of the other 1000 companies doing the same work for a statistical analysis on how their pet firm is doing VS the market on a whole.
Keep in mind, PRIVATE companies do not have to declare anything to anyone other then to the taxation office. So there is no public records of how much money you made. Only publically traded companies (registered with the stock markets) have to release that info. If you are a private company, they can't "buy you out" without coming to your door and offering you money.
But let's assume they decide to come after you for that $1 million you made. First thing they will factor is just what percentage of your business they could grab by closing you down. (some customers will not buy at all, some will goto an other competator, etc). Let's say they figure they can get 25% of your business to sign up with them ($250,000 gain). From there, how much extra man hours are they going to need to service the new clients? How much is the advertising to gain those clients going to cost? How much is the operation (legal/illegal) to shut you down going to cost?
If they cost more then the $250,000 they stand to gain, how many years still they see a profit? Usually in most cases it's not worth the time/hassle to go after a "mom and pop" shop. After all what's 0.000001% of your time (as a mega) really worth?