Agents have been known to check out prospective client's blogs and/or social media. How much might a badly-written blog article influence your decision to request a manuscript? As I wander the webs, I've come across blogs by unpublished writers that don't reflect well any writing skills they may have. And I wonder if writers might put as much care and attention into *all* their writing (blogs, emails, comments, etc.) if they knew prospective agents/publishers/readers were assessing their abilities based on these and not just their query letter.
This answer applies only to me. I'm not sure how other agents work. I like to assume that everyone does things the way I do cause I'm brilliant and all that, but sadly, have discovered that is not the case. (Further empirical evidence I should be Queen of the Known Universe and soon.)
When I get your query and the first 3-5 pages of your novel or memoir, I generally do NOT head over to your website, blog or twitter feed. I request the pages, open a file for you and then after three ice ages have come and gone I read your work and reply.
ONLY if I am interested in taking you on as a client do I start nosing around. Time is a precious commodity here, and if I'm not interested in the book, I'm not going to spend time on your website, blog, or twitter feed cause ..well...why would I? I've got plenty of other writers to torment.
However, and this is a big however, do NOT USE THIS to think you can get sloppy on your website, blog or twitter feed.
Everything you post should be your best work at the time. Don't worry about going back six years and cleaning things up. Obviously you will have gotten better over time.
The big thing about your electronic presence is that it should look active. A blog that no one is reading doesn't help you. A twitter account with no activity (note I said, no activity not too-few followers!) doesn't help you.
Frankly most of what I'm looking for here is whether you are crazypants. Are you going on and on about how slow agents and editors are? Are you making sweeeping political generalities? Are YOU the only thing you talk about?
A good electronic presence is active and social. It's well written, fun to read, and gives me something to retweet or blog about.
And if I take you on as a client you can bet your cute red cowboy boots that one of the first things we'll do is review your web presence across all platforms and ask you to clean up the stuff that needs work. Editors look at this a whole lot more quickly than agents do, that's for sure.