I've participated in giveaways, and have sent my jewelry for free that way. However, I'm now pretty particular about who I align myself with, because I've basically given away some jewelry, with very little exposure gained.
250 followers on a blog, and 300 twitter followers isn't a huge following (then again, that's at least 250 people you wouldn't have reached otherwise, if you want to think of it that way). I have 450 blog followers and 1400 twitter followers, and I still wouldn't feel comfortable asking someone for a product for free to review (though, I have received some free things for review, I didn't really push anyone to give them to me).
So yeah, as already stated, it really depends on the person's following. If you're getting requests from one of those crazy big couponing blogs that have 20,000 followers, I"d say you'd be insane not to take them up on it!
I'm not trying to sound rude in regards to bloggers not having a large following, but they need to do a bit more legwork before they can be taken seriously, and ask for free items. I give money to giveaways and things in interest of networking and getting more followers, and it almost irritates me that people ask for free things JUST because they have a blog.