Blogging, at its height was indeed an effective tool if you knew how to use it. Unfortunately many did not know or chose a sneaky route:.

For those of us who know how to use this method it can bring a lot of targeted traffic and sales.

However the future of blogging as a viable marketing method does hang in the balance.  This is because of abuse and marketers using this tool to blatantly advertise or try to cheat the search engines by making too many non relevant links or ones leading to poor quality content. This has definitely made blogging a much less effective tool.

Google is at this moment accepting blogs leading to viable content on a website but may not for long. Spamdexing with multiple links leading to poor quality and non-relevant content is definitely frowned on by Google and links leading to blatant advertising are also not acceptable to Google.  This means that soon blogs may not be considered by Google and then will not be very effective as a marketing tool.

Right now blogs are still viable but do not use them as a main form of marketing as Google may not recognize them for long. They are losing their effectiveness with readers as well as everyone is using them now. People have only a certain amount of time to read blogs and so many of them are substandard that people have just got tired of them. With a falling off of readership blogs have lost a lot of effectiveness.