Standard formulaic urban fantasy. If you're not picky about anything actually making the least bit of sense, and you're really into the "butt-kicking woman who attracts all kinds of highly attractive violent/egotistical men" thing, I'm sure you'd love it.

This book takes place in a universe that seems to have been developed on the fly then not ironed out for inconsistencies later. "Magic" has basically caused an apocalypse - it eats (some) buildings, for some reason makes some (but not all) technology stop working, and comes and goes in unpredictable waves. Buildings are left in ruins, roads are left in ruins, and yet, everything is business as usual. The government is still in place, there are: doughnuts, Twinkies, new clothes, new cars, luxury apartments, money, mail, phones, mortgages, and fancy restaurants. So, factories are clearly running, imports/exports are being done, despite the fact that they can't predict when anything will stop/start running? The protagonist and a handful of secondary characters also somehow manage to regularly travel the 250-ish miles between Savannah and Atlanta like they're nothing, despite the fact that either magical or internal combustion forms of transportation could give out at any moment, leaving them stranded.

Basically, it seems like the author(s) wanted a world that was functional and pretty much exactly like our world, but with the addition of magic, and with a post-apocalyptic edge to it, but they didn't plan it out fully - possibly because they don't understand exactly what's involved in even just bringing a single doughnut to market from start to finish. The reality is, you don't get to have an apocalypse and a failure of technology and still have everything operating as it was before. It doesn't make sense. This book was a pain in the butt to get through because it was constantly murdering my suspension of disbelief.

They're also inconsistent about the value of money in this world. At one point, complaining about paying $50 for a 250 mile tow (!) then just casually dropping another $50 for a ride across town like it was nothing.

All that said, I can see why it would be a best-seller. It's the Harlequin Romance of the modern era. It's extremely formulaic with bad writing and very questionable scenarios, but it's a formula that works for selling product, which is obviously the goal.