I've sold plenty of art online. I'm not sure what you mean about macros, but here's how it works.
Method 1. All-online transaction. You make the art digitally or scan it, you get paid for it online (PayPal), you deliever it online. How you
find your customer is really up to you. Post your work on Devientart, Tumblr, Facebook, etc and mention you take commissions. The important part is to
post already made artwork. Otherwise, your customers won't have an idea of your style, or may feel like your art is just a cash grab and become uninterested. Make them want you. What I mainly do is I find art selling forums. For example,
GASR is an art site made for IMVU players-- IMVU players loveee buying art, mainly of their characters. I've paid for plane tickets and other things simply by setting up a shop, and allowing customers to order from me.
PAYPAL SAFETY RULES: as of June 1st, PayPal requires artists to be paid as a "business", and not as "friends/family." What does this mean? The "friends/family" option allowed artists to keep their commission money without question. When paid for as a "business", customers can request to withdraw their money. YES, they can take back their money, even after its sent to you. To stop this from happening,
you need to make it required that they check "no shipping delivery" option.
Method 2. Some online, some in-person. So you
could sell everything online. But that's not your only option. In addition to what I mentioned before, people as young as 16-18 have set up booths at conventions and sold their prints. Building your fan base in-person and online will be important if you plan to be an artist in the long term.
Method 3. Selling only 3d art(sculptures, pots, etc) online. These people struggle the most; but it can still be done. Your local art venues are really your best shot. When selling 3d art, people need to see it in person to really appreciate it, and unless you're willing to pay shipping or even international fees, selling online might not be your best option. A devientart and a facebook group would be your best options for publicity.
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Now, I see you talking about prints and framing in particular. Prints are something you sell after you have a fan base. Don't waste money into printing until you get a general idea about how people feel about your art. I don't mean the opinion of friends or family, I mean all people in general, which can be scary, but if you want to sell art, it is necessary. All art is beautiful, but in the real world, not all art is "sellable". Find people who are willing to become your fans, and you'll find people who are willing to buy your art.
