[throwaway10001]

Two things: 1. Putin is sick and tired of US raining (or trying to) on his parade. This would tell US to go F itself, increase Putin's cred in Russia and in many other countries.

2. Snowden has a trove of intel that Russia would love to have.

[michas]

3. Snowden probably already receives paychecks from Russia

[jsmcgd]

If he was receiving pay-checks from Russia for spying, it would probably come with the stipulation that you don't blab to the world's media that you're a spy. At the very least it's implied.