Quentin is an information-hungry Gen Xer, often found lurking in the deepest corners of a client's Google Analytics on a quest to dig up something insightful. With 12+years of SEO experience, he’s the man behind Searcht's 5-star client reviews and a regular contributor to GoDaddy.
I agree with a couple of other answers in that it will depend on the nature of the business and even more specifically the business (and your audience).
So I would recommend you embark on a process of testing different times, email subject lines and messages, review platforms, etc. But document the tests to make sure you understand what is working.
Best practices are a good start to begin testing what gets you results.
As a couple of other answers suggested, providing a direct link to write a review will help. To do this you can create your own Google review link here - https://www.onqmarketing.com.au/google-review-link-generator/.
I would also be careful with how you're asking for reviews and understand that different platforms have different guidelines. For example, Yelp does not like you to solicit and Google definitely doesn't want you paying or compensating for reviews.
I would begin by creating a survey, perhaps through SurveyMonkey, TypeForm or Google Forms.
Using the survey you want to create yourself a detailed user persona. So find out their painpoints, their desires, how they like to shop for their clothing, what style of clothing they're interested in, what do they want to know about tall menswear, would they like to get regular deals/info on tall menswear, find out what social network they spend time on, who influences them, etc, etc. Ask them at the end if they would like to subscribe to an email newsletter.
Of course you need to get responses. I would add an incentive for them to take the time to help you out. Obviously a tall mens clothing voucher makes perfect sense.
Promote it on your website/blog. Post the survey on your Facebook page and then boost it to your specific audience.
Then identify online influencers that might be interested in sharing your survey. If you have a budget advertise your survey on Adwords for relevant search terms.
The survey results will provide you with a detailed picture of your audience. From this you can create a range of blog posts that will directly answer their questions or solve their problems.
Then when you create each post, start promoting it!
Again get back to Facebook and promote it to your target audience. Advertise it on Twitter.
Check out QuuuPromote.
Repurpose the post and submit it to other sites as a guest post with your audience.
I agree with Paul in that you want to find out what problem you can solve. With 30k visitors a week, you should be able to get sufficient responses over a couple of weeks.
I use HotJar to create surveys and polls.
Make sure you structure your survey to get a good understanding of what their specific interest in Turmeric is, if they have other relevant interests and what you can help them with.
You might find that it's not Turmeric, it's in fact weight loss or skin care or anti-inflammatory that they're interested in.
I would then create a content upgrade. That is create a checklist, a guide to Turmeric products or whatever you think may be of value.
Your content upgrade will be the entry-level hook you need to bring your audience into an automated workflow so you can nurture them to a sale.
LeadPages and Drip might be a good combo for you here. With LeadPages you can create a LeadBox as a pop-up on your blog post, asking for their name and email in return for the free upgrade.
With an integration with Drip, you can then email them your content upgrade immediately. This should be the first email in an automated workflow, where you follow up with 2-3 scheduled emails. This might include another link to a guide on Turmeric, weight loss, skincare, etc. Then another perhaps highlighting feedback or a comment from your blog post that demonstrates someone's specific success with Turmeric, etc. (This demonstrates social proof). Then the last email delivers a special offer for Turmeric or another product that you have signed up as an affiliate.
You have the traffic to test every step of this workflow well. After a month, test a different content upgrade to see if that drives more emails. Then test each email in the series to see if you get more opens/clicks. Then of course test different affiliate products (Both physical and digital).
Eventually, if you can maintain the high volume of traffic, you will quickly find a product at the end of the workflow that performs far greater than any other. Now, this is your chance to produce similar yourself, therefore cutting out the middle man. If it's a supplement then look at producing your own line. But it may be a course. Start testing so you can find out.