I buy and sell skill-books, faction/deadspace/officer mods and implants covering all 5 major trade hubs (Jita, Amarr, Dodixie, Hek and Rens) plus several regions that don't have a major trade hub. I play fairly casually and update orders infrequently, often going several days between posting/updating orders. Some characters get updated more often than others and I update sell orders more consistently than buy orders.
In June I made 22 billion after expenses. I made over 16 billion in the first 10 days of the month and broke 200 billion. After that I lost most of my motivation to update orders and make courier contracts. I hardly did anything the rest of the month and only made another 4 billion for the last 20 days of the month. I still haven't gotten the motivation back to spend much time working the market yet and it'll probably be a while longer before I do.
That's my actual current total net worth, I don't pad the numbers by counting ISK I've earned but have since spent and no longer have. That'd be like calling myself a real life millionaire because I've earned over a million dollars during my life when the reality is I've never had anywhere near a million in total.