It is a given that you don't upset your core customers and the point of marketing and advertising by typically spending up to 15% of turnover is to increases product awareness, branding and most of all your sales.
Repeat business is almost always a cheaper cost per sale than new business, which is one of two major reasons that many B2C (business to consumer) and to a lessor extent B2B (business to business) businesses have loyalty cards or other schemes for 2 major reasons. Discounts for customer loyalty and even more importantly understanding the customer interests by tracking what they search for, their potential buying preferences by what they view and actual sales. This provides masses of statistics for using with big data analysis to target online advertising and emails, SMS and phone calls at you. Unless their privacy policy confirms they don't sell your details to 3rd parties, then this can be an extra income stream. Google, Bing, ebay, Amazon, Facebook, Instagram, Snapchat and Twitter if you use them will know alot about you, your interests and buying habits. The recent Facebook scandal has given a slight insight into what they know about you and how much advertising revenue per month you earn for them, typically $82 per person in the US and $50 here, but Google almost certainly knows much more. Those that use personal assistant voice systems are of course providing another great data gathering opportunity along with image analysis for any pictures or videos you put online. In Chrome you can right-click on any image and it will come back with a list of matches, one of a number of methods to check that somebody is who they say they are. There are many abuses on the use of data and that is why the EU's GDPR takes effect on May 25th to address many of these issues with potentially eye watering fines if you drive a coach and horses through them.
It is very rare that a major business will upset its core customers, Gerald Ratner is the famous example and the other is the Conservatives with their dementia tax, but that is not surprising for the politicians as is they had any usable business acumen they wouldn't be earning ~£150k pa as the UK PLC CEO (PM) when the average FTSE 100 CEO has a remuneration package of £4.5m and where a UK PLC board member (MP) earns ~£77k an FTSE 100 board member typically £2.4m.
There are powerful lobby groups which are generally best avoided, unless it addresses the group in a positive way, which includes ethnic minorities, women's groups, US gun lobby, extremes of politics (as Addis have just found out with their newly launched and then quickly withdrawn this weekend USSR branded sports ware) and LBGT as they can very badly affect sales and can easily cost you your job and career.
Offence is very subjective and what offends one group is cool for another group or generation and if it helps shift product it will be used. opps is a good example, cool for under 30's not so cool for selling senior women Sunday school teaching outfits. An advert that suggested men were worse at housework than women, after complaints, was allowed, but another by Strongbow that suggested that men being out with your buddies was more important than being at home with your other half was banned.
Some areas that IMO have very questionable ethics is the heavy advertising of high calorie, high fat, junk food and high sugar and caffeine drinks with little nutritional value, alcohol advertising and gambling, all of which can cause behavioural and addiction problems.