Then and than

I have a few pet peeves, and one that I acquired recently is the abuse of the words then, and than.  I don’t text a lot, and I don’t tweet, but I do read and post on forums, mainly car forums, and sometimes bike, and photography forums.  I have seen an increasing use of the words then and than interchangeably.  Is it because they sound the same, or do people really not know the difference?  I’m often told that poor spelling, grammar and sentence construction is simple laziness, and since the English language is so flexible, and the idea gets conveyed anyway, I should not worry.

Unfortunately I do.  Get bothered, and worry.  To me, badly written posts reflect both ignorance and lack of care and concern for me, the reader.  When I post, I do so, not to impress, but to inform.  And expressing information, or my opinion, in a clear, concise and well written manner makes it easier to read, and hopefully understand, what I am saying.