Amazon Wild for Wiki

Remember when just sold books online? Now, the Seattle-based retailer sells everything on its site, and it’s been a busy investor, too, as it has been putting its weight behind Web service companies.

The latest happened today, whenthe company announced it invested an undisclosed amount of cash in Wikia Inc., which raised $4 million in a Series A earlier this year from Bessemer Venture Partners, OmidyarNetwork and a gaggle of angel investors (Marc Andreessen, Ron Conway, Mitch Kapor, Josh Kopelman and Joichi Ito).

You can read the press release here.

The investment follows Amazon, and CEO Jeff Bezos, investing in other such Web companies as 37Signals, Robot Co-op and Pelago (which was created by a former Amazon exec).

In a BusinessWeek story last month, Bezos outlines his grander scheme.