I have used all the three platforms and thought why not pen down my experiences.
It is very easy and quick to set-up a campaign. Unlike Facebook Ads and LinkedIn Ads, it requires skill and experience to get the correct set of keywords and phrases that match your ads and business. You need to monitor the cost-per-click of each phrase and set it up as broad match or phrase match or exact match. In case you have experience in using the keywords tool then you can start. But, it takes time to optimize the campaign to get the desired ROI and to get better results.
Keywords competition is high and you need to focus on the Quality Score to reduce the cost to attract the clicks. Optimizing the ads is the key here. This can be learnt only through experience.
Another advantage of Adwords is people who click your ad are the people who are searching for your product or service. They searched for a certain term and were looking for it and they have landed on you webpage. Where as in Facebook and LinkedIn, the intention of the person was something else and they click the ad to come to your webpage. Thus, the conversion time to convert the visitor to a customer is longer on these platforms as compared to Adwords.
You can target the ads as per the geographical area and set the time and schedule the display of ads. You also have the display ads where in the ads can be displayed across the Google network of ads. Thus, you reach a wider audience.
The biggest advantage of Adwords is the analytics which Google provides. Google gives lot of data to analyze and fine-tune the campaigns and rectify the mistakes.
It is very easy to setup and maintain. You can target the ads to specific demographic profile as Facebook has all the data with them - age, gender, profession, city, country, marital status...etc. So, you can really target your ads to the niche audience and not just geo specific. This helps in getting quality impressions and clicks.
As stated above, the intent of the person to come on Facebook is different as compared to Google - thus, the CTR is low for the ads but, you get decent impressions. The clicks will increase the fan base thus, ready for direct future promotions on your Facebook page which is at no cost. The time to convert these visitors and/or likes into customers is longer and you need to build a strategy to keep them engaged and thus, converting them to customers. Facebook is a place of fun and leisure unlike Google and LinkedIn. Thus, the ads need to be designed in such a way that you are not just pushing the product or service for them to buy, but trying to engage them and increasing the fan base. Thus, it is difficult to measure the ROI here. The sales cycle is long and effort is required to engage and interact with the prospect.
Facebook ads can be used for more of brand recognition. A click is not necessary for this. As Facebook ads provide more impressions, people see the ad and can register the brand name.
LinkedIn ads is frequented by professionals and in case you are looking at attracting right talent then this is the right place. Also, B2B ads are effective as compared to B2C.
To setup and start the campaign will take some time, as the ads needs to be approved first by the LinkedIn staff. Here as well you can target the ads to the niche audience based on the demographic profile. LinkedIn charges as per impressions and clicks as well. Impression mode will burn out the budget faster we will hardly know if the ad was seen by the person or not. Thus, these are not that effective and economical. The CPC model will not be that effective as stated earlier it all depends on what you are trying to promote. You need to remember the intent of the visitor to LinkedIn and the type of audience that come here.
Reporting tool is also not there. We can download a csv file and we need to do the sorting and filtering ourselves.
To conclude, Adwords is better, if you know how it works and how to steer the campaign. In case you do not have that experience it will cost you. The conversion cycle is quick and you get warm leads. While Facebook, attracts more likes and fan base for you to keep them engage and interact. LinkedIn Ads can be more suitable to reach for senior executives. Lastly, it all depends on what product or service you are trying to promote.