Careless writing

If you were sending out a mass promotional mailing in your own language, would you check what you wrote? Would you maybe get someone else to read it as well - just to make sure there were no errors?

I received an email today from an American company. The writer has confused it's with its:
"I'm interested in pursuing a strategic partnership. XXXX Search and it's family of sites make us the largest online advertising company."

Mistaking it's (=it is) for its (possessive) is a common enough error among native speakers of English. But because it is so common, it's the sort of thing you'd pay particular attention to. If you were sending out an email to a potential customer, surely you'd want to take the time to check it so that you would give a positive impression of your company.

People don't generally have a lot of time to read promotional emails, and one that is carelessly written has a much smaller chance of being taken seriously than one which looks professional.