Um, don't think it's been done to maintain business somehow, as things aren't exactly slow there! At a rough guess, they saw the reaction to the special "Campaign Lady" barrel condoms they were selling & realised that there's a massive market for this kind of thing.
Anyway, using naked/partly naked women to sell paintball products! Smutty innuendo! Shock, horror, the world will end!
Paintball manufacturers have been using sex to sell stuff in the same way for at least 15 years to my knowledge, what's so new about what Smart Parts are doing?