It's all about the rents, baby!
Best perspective yet on Citizens United from Seeing The Forest:
The marketplace is now irrelevant - only company size matters. It is just more efficient to beat your competitors by buying legislation than it is by competing in the marketplace. When you can purchase $1 billion in tax breaks, subsidies, mandates, contracts, whatever by spending a few million on candidates/influence, etc. it just makes more sense to do so. The return on investment is just so much higher than building factories, spending on research, paying employees, and other tedious, time-consuming, capital-intensive work.
For some time companies have recognized that the rewards from lobbying outperform the rewards from competing in the marketplace, and this ruling just amplifies that. This 2006 New York Times article, Google Joins the Lobbying Herd, discussed how Google felt it had “no choice but to get into the arena” to start “spreading its lobbying dollars” around to politicians and quotes Lauren Maddox, a lobbyist for Google, saying the "policy process is an extension of the market battlefield." This supreme court ruling just clinches this shift away from markets.
The game is necessarily going to be to use the superior resources of larger companies to purchase barriers ["rent seeking behavior"] that block smaller, innovative companies from getting anywhere, and force them to be absorbed.
NOTE Via the pessimistic, or realistic, Ian Welsh.