Interesting question. Seems to be possible in Germany, too, judging by the existence of website like ciao.de (though I do not know whether they still pay for product reviews).
Does your country forbid the paying at all, or only the online-only contract that precedes it? In the latter case, you might be able to get away with just not giving a contract -- just a non-contractual `promise' if that's possible -- and paying anyway. For such small sums people may well trust your reputation alone.
