[ghaff]

I had a small "hobbyist" software business once upon a time. I made a point of only deducting expenses that seemed reasonable and not red flags for a software business, and only deducted up to just below my revenue (about $7K/year in the 90s). That seemed safe if maybe somewhat conservative.

Doesn't work for a lot of things (including reputable restaurant reviews) but bloggers also have the opportunity to get free stuff if they get noteworthy enough. Yes, it's a source of bias but so long as everything isn't how this thing they were given for free is fantastic, I don't have a problem with it. I've reviewed books (and a few other things) sent to me and I've given some pretty negative reviews as well as positive ones.