Well, that went about as expected, although the experience should still help her become a better artist, now that she actually knows what she's drawing.
Interesting title.
I'd recommend being a hentai artist, they tend to be quite famous. Either that, or just be or hire a sexy girl to promote your work.
And if you are said sexy girl, well, what the heroine did in this story is certainly one method as well. Trading your body for sales, sort of. (Though if you decide to go this route, make sure to confirm the identity of the other party! Scams aplenty, after all).
Also, thinking she just had to make him cum once is a rookie mistake when it comes to this kind of Hentai situation.
1- draw hentai of megumin
2- profit.
1. Point weird-looking stick at Megumin Hentai collection
2. Say unintelligible gibberish.
3. End with the word: "EXPLOSION!"
*"BOOM!"*
Escape in the resulting confusion.