Independent Booksellers Week is coming to an end, and there's been a great deal of noise about how virtuous little bookshops are in danger of being trampled by wicked Goliath online retailers. Authors are being pilloried for linking their websites to online retailers, and well-meaning publishers are coming up with initiatives to raise the indie profile. This week I learned that 60% of shoppers use bookshops to browse for their online purchase, and that a few authors – presumably ones with ethically impeccable websites – are taking to manning the tills of their local bookstores. (I find this faintly alarming, given just how many weeks it took me to get to grips with the credit card machine and the scanning system.)

I have mixed feelings about all this. As part-owner of a small bookshop (which is thus far being kept afloat by a band of angels posing as loyal customers), I find myself getting into this conversation far more often than I would like, and it turns out to be much harder to make the case for small bookshops when you actually own one. A friend who is currently struggling to find a publisher for her wildly experimental novel announced the other day that she bought everything, "absolutely everything" online and I found myself getting quite shrill. But even as the usual old arguments left my lips I realised I didn't believe a lot of what I was saying. I've thought it all through a little more clearly now, so here, in order from worst to best, are the reasons why I think you should think before you click.

5. To maintain property prices in your area. The argument that little independent shops make your neighbourhood a nicer place to live, so add to the value of your house, is one that I am fond of, but mainly because it feels like very imaginative special pleading.

4. To keep us from folding. How strong an argument is this? Sure, an idiosyncratic little bookshop can be a great thing to have on your local high street, but perhaps not so great that you should feel morally obliged to prop it up if there are significant savings to be had from buying the same product elsewhere.

3. Ethical shopping. If you buy a £10 book from us, a percentage of that money will end up going to the government to spend on education, the NHS, and sending troops to Iraq and keeping us under surveillance at all times. If you buy exactly the same book online for £6, virtually nothing (as we have recently discovered) will contribute to the general good, and you might have to steer clear of articles in the Guardian about the poor conditions in the online retailers' fulfilment centres. But then again, you will have an extra £4 in your pocket.

2. Variety. This is counterintuitive, but you are far more likely to discover a new favourite writer in a small, curated shop with a well-read bookseller who knows your taste than you are in the mind-numbing virtual city of books that online retailers offer. I have yet to meet anyone whose cockles are warmed by the words "customers who bought items in your recent history also bought …".

1. To make sure that good writers continue to be published. This is the reason that matters most to me. Now that the vast majority of books are sold online, the words "your last book only really sold in bookshops – most of which no longer exist" have become commonplace as publishers reject new books from even previously successful authors, particularly if the author is trying something different. If we look at, say, Hilary Mantel's career across a quarter of a century, there is consistency neither in the kind of books she has written (it's hard to think of two more different high-wire acts than A Place of Greater Safety and Beyond Black) nor in her success with critics and readers (The Giant, O'Brien anyone?). It's far from certain that Mantel's publishers would have been able to keep the faith and reap the rewards of her triumphant Thomas Cromwell series without traditional bookselling.

Earlier this week, the American novelist Ruth Ozeki appeared at an event in our shop. She put the point more elegantly: "Shops like this keep a place in their shelves for the books I write – without them I wouldn't have readers."

So this is why you should continue to support your local bookshop (but only if they are doing their job well – no one should have to support an unimaginative or bad-tempered retailer just because they are endangered). Without them, your reading matter will get blander and blander, and if you write a wildly experimental novel, the chances are you will be publishing it yourself. Which is not necessarily a bad thing, but that's a different subject altogether …

• Felicity Rubinstein is a literary agent and bookseller with Lutyens & Rubinstein.