Browning does indeed seem to have a philosophy about success and failure in life. I would suggest that failure for Browning would be in not even trying. This thought appears in a few of his poems such as the dramatic monologue 'The Last Ride Together' in which Browning writes 'Why, all men strive and who succeeds?' This applies to love in this case.
In 'Andrea Del Sarto' he writes 'Ah, but a man's reach should exceed his grasp/ Or what's a heaven for?' For Browning life and art is about striving for something that may be out of reach but the action of striving is a kind of success in itself. Failure for the poet is in not taking part at all. This reflects his own life in which he married someone that was forbidden to marry and then caused a scandal by eloping abroad.