I believe tithing at any percentage is a gift to ourselves more than the Lord, since there is no set percent required of us. In fact, all of the things and ways to live that God calls us to do are for our own benefit in the end anyway, aren't they?
He outlines how we are to remain pure sexually for His benefit or ours? How we should limit our debt for His or ours? How to run our homes, how to rest once a week, how to raise our children, all because He loves us and wants the best for us.
Giving to His kingdom financially doesn't benefit Him. It is Him actually giving to us when we give. It's Him guiding us to the understanding that money doesn't control us or give us meaning. Without giving a meaningless anecdotal story, I'll just say Julie and I learned an invaluable lesson when we were faced with a very difficult financial season. Our collective response was to give more at church. It didn't benefit God, and it certainly didn't make me a hero, but it did take much of the pressure off of us, and we were able to witness the power of God do amazing things afterward that we had no power to do.
I believe everyone can and should give what they can and even more than what they think they can. We may not see a financial windfall as a result, but the freeing of our hearts will be greater than any of that. Not out of obligation and the expectation of something in return, but out of joy as the grip of money's lure is lifted from our hearts.