Sports betting- but only betting when getting bonus bets or profit boosts. (Good short term investment strategy?)

Lately I have been seeing crazy bonus bet offers from sport betting companies lately, so as a result I've been putting in a modest amount of money (I think less than 150 so far, so I can claim bonus bets) so far I have broken even but I still have a lot of open bets and I am likely to make a profit since a lot of my bets have been pretty conservative.