None of us has as much money as we'd probably like. Even if you reject the "consumer culture" of the United States and many other Western nations, you could probably think of some genuinely good things you'd like to do if you could afford it (e.g., funding secular organizations to the point where they could be truly influential). But there are things each and every one of us can do with our money that do not require us to spend any more of it than we already do. Yes, I'm talking about using our power as consumers to influence our world.
I'm not Mittens Romney. Earning $374,000 a year, a figure he considers to be "not very much" money is more than five times the amount I will ever earn in a year. And yet, that does not mean I cannot use what I have to make a difference. I don't even have to spend more in order to do so.
By becoming an educated and thoughtful consumer, I can learn about the companies I am thinking of supporting. When I am considering a purchase, no matter how small, I can ask myself about what other causes I might be indirectly sponsoring. For example, I will not give Chick-fil-A a dime because the causes they support are vile.
A religious influence can be found in many companies. This does not necessarily mean that atheists should avoid every one of them. Not every company on this list is equal. It is far easier for me to imagine buying a Timberland product than shopping at Hobby Lobby. However, I do think that the degree to which religious belief is part of a company may be a relevant consideration for many atheists when trying to decide which companies to support.