Recently we had a conversation about where we ranked among science sites. There are a few measurement services out there, and they all give different numbers ( none of which are truly accurate) plus they all seem to have their own method for determining 'reach' that goes beyond simple traffic.

We decided to compare all the science sites, including ones that are doing different things like articles, blogging and news releases, against each other, using the results from two traffic ranking services, one opt-in popularity service and one service that measures inbound links.

We used traffic rankings first, assuming that they are going to be reasonably inaccurate for everyone the same way. They won't be 50% high for one site and 50% low for another and using two balances out the inequities. One service listed both US and international numbers for a few sites and only US numbers for the vast majority, so we used the US numbers for all to stay fair.

We used four methods of reach because any deficiencies in one measurement are likely balanced out in another. A site with few Technorati links, for example, may have a lot of traffic but may not have bloggers linking back to their articles while Alexa was only available for Internet Explorer until recently so that limited their usage.

We used Compete.com and Quantcast.com for traffic, Alexa.com for general reach and Technorati.com for links. We understand that each one of these probably has detractors. We gathered the pool of science sites by asking everyone we know what they read. Some had to be eliminated because we can't get individual traffic numbers. Example: we like ">Nova and ">Tierney Lab but their URLs resolve to PBS and the NY Times in traffic measuring services so they were excluded. That goes for a lot of sites that resolve to the NIH too.

Each rating service total provided a score between 1 and 100 for each site based on the numeric values they provided. The lowest site received 1 and the highest 100 with all others getting points in even increments between them.

Here, at the end, whittled from 48 at the start to the top 20 ( including a few surprises), are the most popular science sites out there. And we didn't even make the list!

1.

Compete - 4,174,420 Quantcast - 3,288,621

Alexa ranking - 813 / Technorati links - 49,593

2.

Compete - 4,649,129 Quantcast - 5,107,078

Alexa ranking - 1,279 / Technorati links - 2,783

3.

Compete - 3,255,909 Quantcast - 4,182,532

Alexa ranking - 1328 / Technorati links - 13,374

4.

Compete - 1,299,673 Quantcast - 2,252,275

Alexa ranking - 4,677 / Technorati links -37,312

5.

Compete - 677,410 Quantcast - 607,381

Alexa ranking - 8620 / Technorati links - 60,033

6.

Compete - 956,340 Quantcast - 1,481,624

Alexa ranking - 5,271 / Technorati links - 43,774

7. Nature

Compete - 400,759 Quantcast - 467,269

Alexa ranking - 5,266 / Technorati links - 43,859

8. NewScientist

Compete - 496,691 Quantcast - 535,392

Alexa ranking - 5,876 / Technorati links - 40,383

9.

Compete - 326,813 Quantcast - 746,931

Alexa ranking - 11,163 / Technorati links - 28,493

10. Scienceblogs

Compete - 206,632 Quantcast - 597,520

Alexa ranking - 9,775 / Technorati links - 28,483

11.

Compete - 300,158 Quantcast - 169,157

Alexa ranking - 8,730 / Technorati links - 31,257

12. Eurekalert

Compete - 182,142 Quantcast - 232,243

Alexa ranking - 26,409 / Technorati links - 25,262

13.

Compete - 252,244 Quantcast - 291,253

Alexa ranking - 15,175 / Technorati links - 18,992

14.

Compete - 204,604 Quantcast - 156,059

Alexa ranking - 13,087 / Technorati links - 9,814

15.

Compete - 144,916 Quantcast - 123,329

Alexa ranking - 39,750 / Technorati links - 7,525

16. Seed

Compete - 19,875 Quantcast - 12,895

Alexa ranking - 97,684 / Technorati links - 32,709

17.

Compete - 433,478 Quantcast - 699,518

Alexa ranking - 131,258 / Technorati links - 20,925

18.

Compete - 119,505 Quantcast - 98,961

Alexa ranking - 67,392 / Technorati links - 4,407

19.

Compete - 77,576 Quantcast - 129,643

Alexa ranking - 100,971 / Technorati links - 12,800

20.

Compete - 16,123 Quantcast - 31,367

Alexa ranking - 90,202 / Technorati links - 2,053

The logos are all linked from the host sites. If there was no linkable logo, their name is just text.