how to query against nested hstore data type

Hi,

It's my test DB, the version is PostgreSQL 9.4beta2. I'm testing with nested hstore feature.

testdb=# \d+ test
Table "public.test"
Column | Type | Modifiers | Storage | Stats target | Description
--------+--------+-----------+----------+--------------+-------------
id | text | | extended | |
stats | hstore | | extended | |

testdb=# select * from test;
id | stats
---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2b8ea99d60b30 | "www.ask.com"=>"{visits=>2.11221003268,pages=>4.22442006537,duration=>197980.836904}", "www.strawberrynet.com"=>"{visits=>2.11221003268,pages=>4.22442006537,duration=>197980.836904}"
(1 row)

testdb=# select (each(channel)).key,(each(channel)).value from visits;
key | value
-----------------------+----------------------------------------------------------------------
www.ask.com | {visits=>2.11221003268,pages=>4.22442006537,duration=>197980.836904}
www.strawberrynet.com | {visits=>2.11221003268,pages=>4.22442006537,duration=>197980.836904}
(2 rows)

The question is how can I get visits/pages/duration separately from the value column so that I can do a sum on those metrics individually.

Thank you!
Suya