Moz

Moz is rather well known in the online marketing industry. They offer a few well known tools that digital marketers rely upon and they offer a lot of interesting information. Some of the articles you can find are really thought-provoking rather than repeating things put out by Google and other SERPs. Can really help you look at things from a different perspective, though you really need to already have some of the knowledge to connect the dots.

There is no consistancy of the free review from moz, for example, i have compared mutiple sites, if you regularly check them, the DA comes down. For example one of my sites have linking domains 48 and DA-11 after a month now it have linking domains 69 and DA came donwn to 10. All these domains linking are with da 50+, how come the rank came down. While alexa is roaming around a fixed number since about six months. One day it go up by 1000, the next couple of days it goes down by 50,100, and so. After few days it goes up. Ultimately if we check an average rating it stands same.
So what i reccomend is relay in google webmaster guidelines, not go and pay for these fake ranking mechanisms/tools. Please understand your hair is brown or black is just because it is so, not because somebody see it as so.

One of the best SEO resource websites out there.

My complaints are that many SEO tools that you can find for free elsewhere on the Internet are not available for free use on seomoz, on their resource page Internet Marketing Handbook, even though they call it a "free resource page". It's only for paying members, even simple tools like checking keywords and other things. Definitely not impressed with that.

Even so, probably the main reason I love this site is their articles, community and blog. I've used their tools before, and my money is best spent elsewhere. Their tools aren't bad, but they aren't worth it for the price in my opinion.