Alexa.com is an Amazon.com-owned web traffic analytic tool that estimates website usage. It's not as precise or accurate as comScore, MediaMetrics, Nielsen or other more sophisticated Internet measurement tools...but Alexa is good for getting an idea of what search engines are considering "top performers."

The higher a websites Alexa ranking, the higher "authority" that site receives from search engines.

Having higher search engine authority means it is much easily to get found online through search engines.

Viewing the latest rankings, News & Info stations lead the pack with ten within the Top 20. Corus has 9 in the Top 20, while CBC has 4, Astral has 2, NewCap has 2, CTV has 1 and Rogers has 1. Toronto's airport and business station is also in the Top 20 (in March 2007, it was the "station" with the most Alexa web traffic).

Curiously, Virgin Radio doesn't appear to be captured accurately by Alexa. It doesn't include any of the Virgin station on their list. When searching Alexa for the individual Virgin station traffic rankings, each market's stations (Toronto, Montreal, Ottawa, Vancouver) don't show up. Instead, only the main domain (virginradio.com) appears (the station sites are found their sub-domains). Collectively, all Virgin Radio station would rank 26th, just behind CHOM and ahead of Rock 101.

Prior to the Virgin flip, Mix 96 in Montreal was a Top 20 online web traffic radio station.

Here's the latest Alexa search for Canada's top 20 radio station traffic rankings (June 2009):

1) CBC Radio - British Columbia (www.cbc.ca/bc) (CBC)
2) Radio Énergie (www.radioenergie.com) (Astral/Anglo & French AC)
3) CKOI FM 96.9 (ckoi.com) (Corus/Anglo & French Hot AC)
4) CKWX - News 1130 (www.news1130.com) (Rogers/News)
5) VOCM Radio (www.vocm.com) (NewCap/News & Info)
6) CFYZ 1280 AM (www.gtaa.com) (Toronto airport & business)
7) 102.1FM The Edge (www.edge.ca) (Corus/New Rock)
8) CBC Radio (www.cbc.ca/radio) (CBC)
9) Country 105 (www.country105.com) (Corus/Country)
10) Q107 FM (www.q107.com) (Corus/Classic Rock)
11) CKNW 980 AM - Vancouver (www.cknw.com) (Corus/News & Info)
12) CBC Radio 3 (radio3.cbc.ca) (CBC)
13) CHUM 104.5 FM (www.chumfm.com) (CTVglobemedia/Adult CHR/Hot AC)
14) HOT 89.9 FM (www.hot899.com) (NewCap/Rhythmic CHR)
15) CFOX 99.3 - The Fox (www.cfox.com) (Corus/Rock)
16) CBC 102.1 FM Calgary (www.cbc.ca/calgary) (CBC)
17) CJAD 800 AM (www.cjad.com) (Astral/News & Info)
18) CJOB 680 (www.cjob.com) (Corus/News & Info)
19) CISN 103 FM (www.cisnfm.com) (Corus/Country)
20) AM 770 CHQR (www.am770chqr.com) (Corus/News & Info)

Here's a quick link to find all Canadian radio stations streaming online. Or here's another good link.