A feed-in tariff (FIT) program to cover the difference between generation cost and wholesale electricity prices is especially effective at scaling-up new technologies. Combining FITs with a so-called declining clock auction [aka a Dutch or reverse auction], in which the right to sell power to the grid goes to the lowest bidders, provides continuing incentive for WWS [water, wind, and solar] developers to lower costs. As that happens, FITs can be phased out. FITs have been implemented in a number of European countries and a few U.S. states and have been quite successful in stimulating solar power in Germany.
Never mind that FIT's have been implemented in almost all EU countries, not just a number of them -- it is simply a joy to see FITs presented without further comment as the main way to do things. I suppose we will just have to accept all of the other tinkering -- the combination of FITs with auctions, net-metering, etc. -- that American proponents of FITs seems so fond of. If you, like me, prefer your FITs straight with no chaser, keep in mind that Spain also has a kind of "floating bonus" closely related to what Americans would call the "merit order price" for wind power. And Spain has done quite well with wind.