Hands up those marketers who planned for a situation where some sectors simply cannot do business at all, where demand is constrained by government edict, and no amount of advertising will get people into your store, restaurant, hotel or plane. Me neither.

So, what should brands do in the Covid crisis? First, the things not to do:

1. Don?t assume you have to say anything

Maybe you should just save the money. Too many businesses seem to see this as a pretext to use their email database. Banks and retailers with whom I have the most tenuous connection ? I can?t call it a relationship ? are emailing to reassure me they are here for me. So, apparently, is the motor dealership where I once bought a car. Cool, cool.

It?s a lot more public, and more expensive, for those brands seemingly competing for title of Most Vacuous on television, as demonstrated in this compilation.

2. Don?t make it about you (unless it is).

Believing advertising has an impact means accepting that its impact can be negative. It?s hard to advertise without making it about you, but in a crisis that?s not going to land well unless it?s really worth saying. Test that premise. Who needs to hear this message? Do they need it now? Can it be targeted to those who really need it rather than broadcast? Does it look self-serving if we say this now?

There are some things you can do

1. Be relevant

Top marks to John Lewis for emails that are both relevant and stimulating ? garden accessories, things you can put on your balcony, outdoor games. Tesco is advertising its early-morning opening hours which are restricted to NHS and social care workers.?This is not virtue-signalling, it?s useful both to those who will be allowed in at that time and those who won?t.

Retailers and banks are emailing their access arrangements, which is marginally useful and not overly intrusive. Airlines telling me about their cleaning practices are less welcome ? they could wait until I ask. ?I have yet to see a bank email me personally or as a business to tell us how we can apply for government assistance or a business support loan.

2. Remove friction

This is always a worthwhile goal. People love those little tweaks that make things easy. Sometimes people can tell you in research what they?d like, but humans are adaptable, so we tend to accept and accommodate rather than complain. Companies must challenge their own assumptions and processes. Apple is a master of this: unlocking a phone with a pin code seemed fine until we got fingerprint recognition. Then face ID made that feel like a faff.

There?s a clear divide between those businesses that have been proactive on behalf of customers and those that have maintained friction to protect short term revenue. Most gym groups automatically suspended membership when going to the gym became a proscribed activity. By contrast, even though pay-TV sport channels had no live sport to offer, Sky, Virgin Media and BT Sport waited for the customer to make the effort to cancel. Looking at direct competitors in the sector can give a false sense of security to businesses. Most customers only have one of those in our home; our comparisons are with brands in other sectors. It?s not a capability issue, either. Once live sport resumes Sky will automatically restart your subscription. Yes, taking your money is automated.

3. Be useful

Some businesses that can?t run as normal are doing impressive things, repurposing to serve key workers or to manufacture critical goods such as personal protective equipment. Some that can?t do this are donating hard cash. British Airways staff have been serving breakfast in uniform to NHS staff, which is a lovely stunt, cynical perhaps but still appealing, and garnering some good media coverage. It is tempting to announce whatever you?re doing. But you don?t have to tell everyone, right now. It may be something for shareholders, or people in the loyalty scheme. It might, in any case, be better to let someone else publicise your good work. Or wait to be asked. Or tell us after the crisis, when you have the full story.

On the other hand, some smaller businesses are seizing the moment to get attention. A sex fetish website called MedfetUK announced on Twitter that it had donated its stock of PPE for more conventional use during the pandemic. It?s not clear what they hope to gain, though. Surely this is relevant only to customers and potential customers – and for them it?s the unwelcome news that their favourite fetish items will be out of stock for the foreseeable.

4. Think long term

There is robust evidence that advertising in a recession builds brand value which pays back when the economy recovers. But perhaps the most important opportunity, available to even the most cash-strapped business, is to use the time to rethink. Marketing is not just communications, after all. Revisit those hefty seminal pieces of work like market segmentation that can yield gems if you have the luxury of time to explore them. Look again at the fundamentals of your brand, your category, your business model. Finally, we are free from running from meeting to meeting. What a chance to innovate.